Vulnerability-Lookup

FKIE_CVE-2025-40206

Vulnerability from fkie_nvd - Published: 2025-11-12 22:15 - Updated: 2026-08-23 13:16

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_objref: validate objref and objrefmap expressions Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls: BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12) [...] Call Trace: __find_rr_leaf+0x99/0x230 fib6_table_lookup+0x13b/0x2d0 ip6_pol_route+0xa4/0x400 fib6_rule_lookup+0x156/0x240 ip6_route_output_flags+0xc6/0x150 __nf_ip6_route+0x23/0x50 synproxy_send_tcp_ipv6+0x106/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 nft_synproxy_do_eval+0x263/0x310 nft_do_chain+0x5a8/0x5f0 [nf_tables nft_do_chain_inet+0x98/0x110 nf_hook_slow+0x43/0xc0 __ip6_local_out+0xf0/0x170 ip6_local_out+0x17/0x70 synproxy_send_tcp_ipv6+0x1a2/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 [...] Implement objref and objrefmap expression validate functions. Currently, only NFT_OBJECT_SYNPROXY object type requires validation. This will also handle a jump to a chain using a synproxy object from the OUTPUT hook. Now when trying to reference a synproxy object in the OUTPUT hook, nft will produce the following error: synproxy_crash.nft: Error: Could not process rule: Operation not supported synproxy name mysynproxy ^^^^^^^^^^^^^^^^^^^^^^^^

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0028e0134c64d9ed21728341a74fcfc59cd0f944
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4c1cf72ec10be5a9ad264650cadffa1fbce6fabd
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f31bcea12222a26d6f151df9c4a6d21f2eec1724
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f359b809d54c6e3dd1d039b97e0b68390b0e53e4

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_objref.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f31bcea12222a26d6f151df9c4a6d21f2eec1724",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "0028e0134c64d9ed21728341a74fcfc59cd0f944",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "4c1cf72ec10be5a9ad264650cadffa1fbce6fabd",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "f359b809d54c6e3dd1d039b97e0b68390b0e53e4",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_objref.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "lessThan": "5.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_objref: validate objref and objrefmap expressions\n\nReferencing a synproxy stateful object from OUTPUT hook causes kernel\ncrash due to infinite recursive calls:\n\nBUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12)\n[...]\nCall Trace:\n __find_rr_leaf+0x99/0x230\n fib6_table_lookup+0x13b/0x2d0\n ip6_pol_route+0xa4/0x400\n fib6_rule_lookup+0x156/0x240\n ip6_route_output_flags+0xc6/0x150\n __nf_ip6_route+0x23/0x50\n synproxy_send_tcp_ipv6+0x106/0x200\n synproxy_send_client_synack_ipv6+0x1aa/0x1f0\n nft_synproxy_do_eval+0x263/0x310\n nft_do_chain+0x5a8/0x5f0 [nf_tables\n nft_do_chain_inet+0x98/0x110\n nf_hook_slow+0x43/0xc0\n __ip6_local_out+0xf0/0x170\n ip6_local_out+0x17/0x70\n synproxy_send_tcp_ipv6+0x1a2/0x200\n synproxy_send_client_synack_ipv6+0x1aa/0x1f0\n[...]\n\nImplement objref and objrefmap expression validate functions.\n\nCurrently, only NFT_OBJECT_SYNPROXY object type requires validation.\nThis will also handle a jump to a chain using a synproxy object from the\nOUTPUT hook.\n\nNow when trying to reference a synproxy object in the OUTPUT hook, nft\nwill produce the following error:\n\nsynproxy_crash.nft: Error: Could not process rule: Operation not supported\n  synproxy name mysynproxy\n  ^^^^^^^^^^^^^^^^^^^^^^^^"
    }
  ],
  "id": "CVE-2025-40206",
  "lastModified": "2026-08-23T13:16:26.737",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-11-12T22:15:47.893",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0028e0134c64d9ed21728341a74fcfc59cd0f944"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4c1cf72ec10be5a9ad264650cadffa1fbce6fabd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f31bcea12222a26d6f151df9c4a6d21f2eec1724"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f359b809d54c6e3dd1d039b97e0b68390b0e53e4"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}

CVE-2025-40206 (GCVE-0-2025-40206)

Vulnerability from cvelistv5 – Published: 2025-11-12 21:56 – Updated: 2026-08-23 12:45

Title

netfilter: nft_objref: validate objref and objrefmap expressions

Summary

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/f31bcea12222a26d6…
https://git.kernel.org/stable/c/0028e0134c64d9ed2…
https://git.kernel.org/stable/c/7ea55a44493a5a36c…
https://git.kernel.org/stable/c/4c1cf72ec10be5a9a…
https://git.kernel.org/stable/c/f359b809d54c6e3dd…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: ee394f96ad7517fbc0de9106dcc7ce9efb14f264 , < f31bcea12222a26d6f151df9c4a6d21f2eec1724 (git) Affected: ee394f96ad7517fbc0de9106dcc7ce9efb14f264 , < 0028e0134c64d9ed21728341a74fcfc59cd0f944 (git) Affected: ee394f96ad7517fbc0de9106dcc7ce9efb14f264 , < 7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0 (git) Affected: ee394f96ad7517fbc0de9106dcc7ce9efb14f264 , < 4c1cf72ec10be5a9ad264650cadffa1fbce6fabd (git) Affected: ee394f96ad7517fbc0de9106dcc7ce9efb14f264 , < f359b809d54c6e3dd1d039b97e0b68390b0e53e4 (git)
Linux	Linux	Affected: 5.4 Unaffected: 0 , < 5.4 (semver) Unaffected: 6.1.184 , ≤ 6.1.* (semver) Unaffected: 6.6.113 , ≤ 6.6.* (semver) Unaffected: 6.12.54 , ≤ 6.12.* (semver) Unaffected: 6.17.4 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_objref.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f31bcea12222a26d6f151df9c4a6d21f2eec1724",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "0028e0134c64d9ed21728341a74fcfc59cd0f944",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "4c1cf72ec10be5a9ad264650cadffa1fbce6fabd",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            },
            {
              "lessThan": "f359b809d54c6e3dd1d039b97e0b68390b0e53e4",
              "status": "affected",
              "version": "ee394f96ad7517fbc0de9106dcc7ce9efb14f264",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_objref.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "lessThan": "5.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.184",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.113",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.54",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.4",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_objref: validate objref and objrefmap expressions\n\nReferencing a synproxy stateful object from OUTPUT hook causes kernel\ncrash due to infinite recursive calls:\n\nBUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12)\n[...]\nCall Trace:\n __find_rr_leaf+0x99/0x230\n fib6_table_lookup+0x13b/0x2d0\n ip6_pol_route+0xa4/0x400\n fib6_rule_lookup+0x156/0x240\n ip6_route_output_flags+0xc6/0x150\n __nf_ip6_route+0x23/0x50\n synproxy_send_tcp_ipv6+0x106/0x200\n synproxy_send_client_synack_ipv6+0x1aa/0x1f0\n nft_synproxy_do_eval+0x263/0x310\n nft_do_chain+0x5a8/0x5f0 [nf_tables\n nft_do_chain_inet+0x98/0x110\n nf_hook_slow+0x43/0xc0\n __ip6_local_out+0xf0/0x170\n ip6_local_out+0x17/0x70\n synproxy_send_tcp_ipv6+0x1a2/0x200\n synproxy_send_client_synack_ipv6+0x1aa/0x1f0\n[...]\n\nImplement objref and objrefmap expression validate functions.\n\nCurrently, only NFT_OBJECT_SYNPROXY object type requires validation.\nThis will also handle a jump to a chain using a synproxy object from the\nOUTPUT hook.\n\nNow when trying to reference a synproxy object in the OUTPUT hook, nft\nwill produce the following error:\n\nsynproxy_crash.nft: Error: Could not process rule: Operation not supported\n  synproxy name mysynproxy\n  ^^^^^^^^^^^^^^^^^^^^^^^^"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The flaw is enabled through an nftables ruleset installed over the NFNL_SUBSYS_NFTABLES netlink socket, and triggered by a locally-generated TCP SYN traversing the OUTPUT hook. Per netfilter/nftables convention this is a local attack surface, not a remotely reachable one.\nAC:L - Exploitation is fully deterministic \u2014 add a synproxy object reference to an OUTPUT base chain and emit any TCP SYN; there is no race, no memory-layout dependency, and no bound on the recursion depth. CONFIG_NFT_SYNPROXY is standard and autoloadable on distribution kernels.\nPR:L - nfnetlink_rcv checks netlink_net_capable(skb, CAP_NET_ADMIN), which evaluates against the network namespace\u0027s owning user namespace, so any unprivileged local user obtains it via `unshare -Urn`; nft_synproxy_do_init imposes no init_user_ns requirement. The resulting stack overflow is not confined to the namespace and takes down the host.\nUI:N - The attacker performs both steps \u2014 installing the rule and emitting the triggering SYN \u2014 with no action required from any other user or administrator.\nS:U - The recursion, the stack exhaustion, and the resulting panic all occur within the kernel\u0027s own security authority; no hypervisor, IOMMU, or other trust boundary is crossed.\nC:H - The unbounded recursion exhausts the kernel stack, and on the many embedded/IoT/automotive configurations lacking CONFIG_VMAP_STACK (arm32 without ARM_HAS_GROUP_RELOCS, and architectures with no VMAP_STACK support) it runs past the stack into adjacent kernel pages rather than into a guard page, corrupting neighbouring structures that can be leveraged for kernel memory disclosure.\nI:H - On those same non-VMAP_STACK configurations the overrun writes attacker-influenced frame contents \u2014 struct flowi6 built from the attacker\u0027s SYN addresses/ports, synproxy_options with attacker-chosen MSS/wscale/timestamps, and nft_regs \u2014 into adjacent kernel memory, and on architectures where thread_info sits at the stack base it clobbers that first, yielding an exploitable corruption primitive.\nA:H - The infinite recursion reliably exhausts the kernel stack and hits the guard page, producing an immediate kernel panic as shown in the reporter\u0027s trace. This is a complete denial of service triggerable at will by an unprivileged local user."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-23T12:45:25.956Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f31bcea12222a26d6f151df9c4a6d21f2eec1724"
        },
        {
          "url": "https://git.kernel.org/stable/c/0028e0134c64d9ed21728341a74fcfc59cd0f944"
        },
        {
          "url": "https://git.kernel.org/stable/c/7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0"
        },
        {
          "url": "https://git.kernel.org/stable/c/4c1cf72ec10be5a9ad264650cadffa1fbce6fabd"
        },
        {
          "url": "https://git.kernel.org/stable/c/f359b809d54c6e3dd1d039b97e0b68390b0e53e4"
        }
      ],
      "title": "netfilter: nft_objref: validate objref and objrefmap expressions",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40206",
    "datePublished": "2025-11-12T21:56:35.675Z",
    "dateReserved": "2025-04-16T07:20:57.179Z",
    "dateUpdated": "2026-08-23T12:45:25.956Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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FKIE_CVE-2025-40206

CVE-2025-40206 (GCVE-0-2025-40206)

Tags

Sightings

Nomenclature

Related by attack behaviour