CWE-362
Allowed-with-ReviewConcurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Abstraction: Class · Status: Draft
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
2899 vulnerabilities reference this CWE, most recent first.
GHSA-7627-2WXQ-JRMH
Vulnerability from github – Published: 2022-05-24 17:32 – Updated: 2022-05-24 17:32An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a host OS denial of service, achieve data corruption, or possibly gain privileges by exploiting a race condition that leads to a use-after-free involving 2MiB and 1GiB superpages.
{
"affected": [],
"aliases": [
"CVE-2020-27672"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-10-22T21:15:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a host OS denial of service, achieve data corruption, or possibly gain privileges by exploiting a race condition that leads to a use-after-free involving 2MiB and 1GiB superpages.",
"id": "GHSA-7627-2wxq-jrmh",
"modified": "2022-05-24T17:32:01Z",
"published": "2022-05-24T17:32:01Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-27672"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XIK57QJOVOPWH6RFRNMGOBCROBCKMDG2"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202011-06"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2020/dsa-4804"
},
{
"type": "WEB",
"url": "https://xenbits.xen.org/xsa/advisory-345.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00075.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00025.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/01/19/7"
},
{
"type": "WEB",
"url": "http://xenbits.xen.org/xsa/advisory-345.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-76HJ-MCWF-QJ3W
Vulnerability from github – Published: 2025-05-01 15:31 – Updated: 2025-11-07 18:30In the Linux kernel, the following vulnerability has been resolved:
perf/x86/amd: Fix crash due to race between amd_pmu_enable_all, perf NMI and throttling
amd_pmu_enable_all() does:
if (!test_bit(idx, cpuc->active_mask))
continue;
amd_pmu_enable_event(cpuc->events[idx]);
A perf NMI of another event can come between these two steps. Perf NMI handler internally disables and enables all events, including the one which nmi-intercepted amd_pmu_enable_all() was in process of enabling. If that unintentionally enabled event has very low sampling period and causes immediate successive NMI, causing the event to be throttled, cpuc->events[idx] and cpuc->active_mask gets cleared by x86_pmu_stop(). This will result in amd_pmu_enable_event() getting called with event=NULL when amd_pmu_enable_all() resumes after handling the NMIs. This causes a kernel crash:
BUG: kernel NULL pointer dereference, address: 0000000000000198 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] Call Trace: amd_pmu_enable_all+0x68/0xb0 ctx_resched+0xd9/0x150 event_function+0xb8/0x130 ? hrtimer_start_range_ns+0x141/0x4a0 ? perf_duration_warn+0x30/0x30 remote_function+0x4d/0x60 __flush_smp_call_function_queue+0xc4/0x500 flush_smp_call_function_queue+0x11d/0x1b0 do_idle+0x18f/0x2d0 cpu_startup_entry+0x19/0x20 start_secondary+0x121/0x160 secondary_startup_64_no_verify+0xe5/0xeb
amd_pmu_disable_all()/amd_pmu_enable_all() calls inside perf NMI handler were recently added as part of BRS enablement but I'm not sure whether we really need them. We can just disable BRS in the beginning and enable it back while returning from NMI. This will solve the issue by not enabling those events whose active_masks are set but are not yet enabled in hw pmu.
{
"affected": [],
"aliases": [
"CVE-2022-49781"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T15:16:01Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/amd: Fix crash due to race between amd_pmu_enable_all, perf NMI and throttling\n\namd_pmu_enable_all() does:\n\n if (!test_bit(idx, cpuc-\u003eactive_mask))\n continue;\n\n amd_pmu_enable_event(cpuc-\u003eevents[idx]);\n\nA perf NMI of another event can come between these two steps. Perf NMI\nhandler internally disables and enables _all_ events, including the one\nwhich nmi-intercepted amd_pmu_enable_all() was in process of enabling.\nIf that unintentionally enabled event has very low sampling period and\ncauses immediate successive NMI, causing the event to be throttled,\ncpuc-\u003eevents[idx] and cpuc-\u003eactive_mask gets cleared by x86_pmu_stop().\nThis will result in amd_pmu_enable_event() getting called with event=NULL\nwhen amd_pmu_enable_all() resumes after handling the NMIs. This causes a\nkernel crash:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000198\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n [...]\n Call Trace:\n \u003cTASK\u003e\n amd_pmu_enable_all+0x68/0xb0\n ctx_resched+0xd9/0x150\n event_function+0xb8/0x130\n ? hrtimer_start_range_ns+0x141/0x4a0\n ? perf_duration_warn+0x30/0x30\n remote_function+0x4d/0x60\n __flush_smp_call_function_queue+0xc4/0x500\n flush_smp_call_function_queue+0x11d/0x1b0\n do_idle+0x18f/0x2d0\n cpu_startup_entry+0x19/0x20\n start_secondary+0x121/0x160\n secondary_startup_64_no_verify+0xe5/0xeb\n \u003c/TASK\u003e\n\namd_pmu_disable_all()/amd_pmu_enable_all() calls inside perf NMI handler\nwere recently added as part of BRS enablement but I\u0027m not sure whether\nwe really need them. We can just disable BRS in the beginning and enable\nit back while returning from NMI. This will solve the issue by not\nenabling those events whose active_masks are set but are not yet enabled\nin hw pmu.",
"id": "GHSA-76hj-mcwf-qj3w",
"modified": "2025-11-07T18:30:25Z",
"published": "2025-05-01T15:31:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49781"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/baa014b9543c8e5e94f5d15b66abfe60750b8284"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fd5e454b856ed86b090336e269695d9908609b71"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-76PX-VGR2-5HQ4
Vulnerability from github – Published: 2025-12-08 09:30 – Updated: 2025-12-08 09:30Multi-thread race condition vulnerability in the camera framework module. Impact: Successful exploitation of this vulnerability may affect availability.
{
"affected": [],
"aliases": [
"CVE-2025-66322"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-08T08:15:53Z",
"severity": "MODERATE"
},
"details": "Multi-thread race condition vulnerability in the camera framework module. Impact: Successful exploitation of this vulnerability may affect availability.",
"id": "GHSA-76px-vgr2-5hq4",
"modified": "2025-12-08T09:30:18Z",
"published": "2025-12-08T09:30:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-66322"
},
{
"type": "WEB",
"url": "https://consumer.huawei.com/en/support/bulletin/2025/12"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-76R5-XVFG-3GJ2
Vulnerability from github – Published: 2022-10-16 12:00 – Updated: 2022-10-19 12:00A vulnerability has been found in Linux Kernel and classified as problematic. This vulnerability affects the function kcm_tx_work of the file net/kcm/kcmsock.c of the component kcm. The manipulation leads to race condition. It is recommended to apply a patch to fix this issue. VDB-211018 is the identifier assigned to this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2022-3521"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-10-16T10:15:00Z",
"severity": "LOW"
},
"details": "A vulnerability has been found in Linux Kernel and classified as problematic. This vulnerability affects the function kcm_tx_work of the file net/kcm/kcmsock.c of the component kcm. The manipulation leads to race condition. It is recommended to apply a patch to fix this issue. VDB-211018 is the identifier assigned to this vulnerability.",
"id": "GHSA-76r5-xvfg-3gj2",
"modified": "2022-10-19T12:00:24Z",
"published": "2022-10-16T12:00:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-3521"
},
{
"type": "WEB",
"url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ec7eede369fe5b0d085ac51fdbb95184f87bfc6c"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/12/msg00031.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/12/msg00034.html"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.211018"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-76X2-J576-5G7R
Vulnerability from github – Published: 2025-03-12 00:31 – Updated: 2025-03-12 00:31In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix a data-race around sysctl_tcp_ecn_fallback.
While reading sysctl_tcp_ecn_fallback, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader.
{
"affected": [],
"aliases": [
"CVE-2022-49630"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-26T07:01:38Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Fix a data-race around sysctl_tcp_ecn_fallback.\n\nWhile reading sysctl_tcp_ecn_fallback, it can be changed concurrently.\nThus, we need to add READ_ONCE() to its reader.",
"id": "GHSA-76x2-j576-5g7r",
"modified": "2025-03-12T00:31:47Z",
"published": "2025-03-12T00:31:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49630"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/12b8d9ca7e678abc48195294494f1815b555d658"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1ec3d6c2626ee6e1b36b7bd006873a271406ba61"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8bcf7339f2cf70ea4461df6ea045d1aadfabfa11"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-772J-XVF9-QPF5
Vulnerability from github – Published: 2022-08-24 00:00 – Updated: 2024-11-26 16:10A race condition flaw was found in ansible-runner, where an attacker could watch for rapid creation and deletion of a temporary directory, substitute their directory at that name, and then have access to ansible-runner's private_data_dir the next time ansible-runner made use of the private_data_dir. The highest Threat out of this flaw is to integrity and confidentiality.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "ansible-runner"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0"
},
{
"fixed": "2.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-3702"
],
"database_specific": {
"cwe_ids": [
"CWE-362",
"CWE-377"
],
"github_reviewed": true,
"github_reviewed_at": "2022-09-01T22:17:50Z",
"nvd_published_at": "2022-08-23T16:15:00Z",
"severity": "MODERATE"
},
"details": "A race condition flaw was found in ansible-runner, where an attacker could watch for rapid creation and deletion of a temporary directory, substitute their directory at that name, and then have access to ansible-runner\u0027s private_data_dir the next time ansible-runner made use of the private_data_dir. The highest Threat out of this flaw is to integrity and confidentiality.",
"id": "GHSA-772j-xvf9-qpf5",
"modified": "2024-11-26T16:10:26Z",
"published": "2022-08-24T00:00:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-3702"
},
{
"type": "PACKAGE",
"url": "https://github.com/ansible/ansible-runner/pull/742"
},
{
"type": "WEB",
"url": "https://github.com/ansible/ansible-runner/pull/742/commits"
},
{
"type": "WEB",
"url": "https://github.com/ansible/ansible-runner/commit/93e95a3df9021a38010386d07df121392d249253"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2021-3702"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1977965"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/ansible-runner/PYSEC-2022-43068.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "ansible-runner vulnerable to Race Condition"
}
GHSA-772Q-FWQP-96RG
Vulnerability from github – Published: 2024-11-05 18:32 – Updated: 2024-11-08 15:31In the Linux kernel, the following vulnerability has been resolved:
nvme-pci: fix race condition between reset and nvme_dev_disable()
nvme_dev_disable() modifies the dev->online_queues field, therefore nvme_pci_update_nr_queues() should avoid racing against it, otherwise we could end up passing invalid values to blk_mq_update_nr_hw_queues().
WARNING: CPU: 39 PID: 61303 at drivers/pci/msi/api.c:347 pci_irq_get_affinity+0x187/0x210 Workqueue: nvme-reset-wq nvme_reset_work [nvme] RIP: 0010:pci_irq_get_affinity+0x187/0x210 Call Trace: ? blk_mq_pci_map_queues+0x87/0x3c0 ? pci_irq_get_affinity+0x187/0x210 blk_mq_pci_map_queues+0x87/0x3c0 nvme_pci_map_queues+0x189/0x460 [nvme] blk_mq_update_nr_hw_queues+0x2a/0x40 nvme_reset_work+0x1be/0x2a0 [nvme]
Fix the bug by locking the shutdown_lock mutex before using dev->online_queues. Give up if nvme_dev_disable() is running or if it has been executed already.
{
"affected": [],
"aliases": [
"CVE-2024-50135"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-11-05T18:15:16Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-pci: fix race condition between reset and nvme_dev_disable()\n\nnvme_dev_disable() modifies the dev-\u003eonline_queues field, therefore\nnvme_pci_update_nr_queues() should avoid racing against it, otherwise\nwe could end up passing invalid values to blk_mq_update_nr_hw_queues().\n\n WARNING: CPU: 39 PID: 61303 at drivers/pci/msi/api.c:347\n pci_irq_get_affinity+0x187/0x210\n Workqueue: nvme-reset-wq nvme_reset_work [nvme]\n RIP: 0010:pci_irq_get_affinity+0x187/0x210\n Call Trace:\n \u003cTASK\u003e\n ? blk_mq_pci_map_queues+0x87/0x3c0\n ? pci_irq_get_affinity+0x187/0x210\n blk_mq_pci_map_queues+0x87/0x3c0\n nvme_pci_map_queues+0x189/0x460 [nvme]\n blk_mq_update_nr_hw_queues+0x2a/0x40\n nvme_reset_work+0x1be/0x2a0 [nvme]\n\nFix the bug by locking the shutdown_lock mutex before using\ndev-\u003eonline_queues. Give up if nvme_dev_disable() is running or if\nit has been executed already.",
"id": "GHSA-772q-fwqp-96rg",
"modified": "2024-11-08T15:31:12Z",
"published": "2024-11-05T18:32:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-50135"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/26bc0a81f64ce00fc4342c38eeb2eddaad084dd2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4ed32cc0939b64e3d7b48c8c0d63ea038775f304"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b33e49a5f254474b33ce98fd45dd0ffdc247a0be"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7768-MFM4-9CMV
Vulnerability from github – Published: 2022-05-24 17:22 – Updated: 2022-05-24 17:22When browsing a malicious page, a race condition in our SharedWorkerService could occur and lead to a potentially exploitable crash. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.
{
"affected": [],
"aliases": [
"CVE-2020-12405"
],
"database_specific": {
"cwe_ids": [
"CWE-362",
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-07-09T15:15:00Z",
"severity": "LOW"
},
"details": "When browsing a malicious page, a race condition in our SharedWorkerService could occur and lead to a potentially exploitable crash. This vulnerability affects Thunderbird \u003c 68.9.0, Firefox \u003c 77, and Firefox ESR \u003c 68.9.",
"id": "GHSA-7768-mfm4-9cmv",
"modified": "2022-05-24T17:22:37Z",
"published": "2022-05-24T17:22:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-12405"
},
{
"type": "WEB",
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1631618"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/4421-1"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2020-20"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2020-21"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2020-22"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-77F5-F59V-G352
Vulnerability from github – Published: 2025-03-12 00:31 – Updated: 2025-03-12 00:31In the Linux kernel, the following vulnerability has been resolved:
sysctl: Fix data races in proc_douintvec().
A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing.
This patch changes proc_douintvec() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_douintvec() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side.
{
"affected": [],
"aliases": [
"CVE-2022-49641"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-26T07:01:39Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsysctl: Fix data races in proc_douintvec().\n\nA sysctl variable is accessed concurrently, and there is always a chance\nof data-race. So, all readers and writers need some basic protection to\navoid load/store-tearing.\n\nThis patch changes proc_douintvec() to use READ_ONCE() and WRITE_ONCE()\ninternally to fix data-races on the sysctl side. For now, proc_douintvec()\nitself is tolerant to a data-race, but we still need to add annotations on\nthe other subsystem\u0027s side.",
"id": "GHSA-77f5-f59v-g352",
"modified": "2025-03-12T00:31:48Z",
"published": "2025-03-12T00:31:48Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49641"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4762b532ec9539755aab61445d5da6e1926ccb99"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/630c76850d554d7140232e71b5d1663e88cffb54"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d335db59f7fb3353f56e52371f1ee796ae9c8f09"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d5d54714e329f646bd7af4994fc427d88ee68936"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-77G8-PQ4G-F4JV
Vulnerability from github – Published: 2022-05-24 17:29 – Updated: 2022-10-01 00:00An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.
{
"affected": [],
"aliases": [
"CVE-2020-25604"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-09-23T22:15:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn\u0027t acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.",
"id": "GHSA-77g8-pq4g-f4jv",
"modified": "2022-10-01T00:00:25Z",
"published": "2022-05-24T17:29:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-25604"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202011-06"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2020/dsa-4769"
},
{
"type": "WEB",
"url": "https://xenbits.xen.org/xsa/advisory-336.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Mitigation
Use thread-safe capabilities such as the data access abstraction in Spring.
Mitigation
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
- Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Mitigation
When using multithreading and operating on shared variables, only use thread-safe functions.
Mitigation
Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write.
Mitigation
Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.
Mitigation
Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.
Mitigation
Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop.
Mitigation
Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help.
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
CAPEC-26: Leveraging Race Conditions
The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.
CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. A typical example is file access. The adversary can leverage a file access race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary could replace or modify the file, causing the application to behave unexpectedly.