CWE-347
AllowedImproper Verification of Cryptographic Signature
Abstraction: Base · Status: Draft
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
1336 vulnerabilities reference this CWE, most recent first.
GHSA-CHQ4-235Q-JP7W
Vulnerability from github – Published: 2025-12-09 18:30 – Updated: 2026-06-09 12:32An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through 7.6.4, FortiWeb 7.4.0 through 7.4.9 may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.
{
"affected": [],
"aliases": [
"CVE-2025-59719"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-09T18:15:55Z",
"severity": "CRITICAL"
},
"details": "An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through 7.6.4, FortiWeb 7.4.0 through 7.4.9 may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.",
"id": "GHSA-chq4-235q-jp7w",
"modified": "2026-06-09T12:32:00Z",
"published": "2025-12-09T18:30:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59719"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-864900.html"
},
{
"type": "WEB",
"url": "https://fortiguard.fortinet.com/psirt/FG-IR-25-647"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CHW7-Q7HH-9VC2
Vulnerability from github – Published: 2022-05-24 17:46 – Updated: 2022-07-11 00:00Union Pay up to 1.2.0, for web based versions contains a CWE-347: Improper Verification of Cryptographic Signature vulnerability, allows attackers to shop for free in merchants' websites and mobile apps, via a crafted authentication code (MAC) which is generated based on a secret key which is NULL.
{
"affected": [],
"aliases": [
"CVE-2020-23533"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-04-06T16:15:00Z",
"severity": "HIGH"
},
"details": "Union Pay up to 1.2.0, for web based versions contains a CWE-347: Improper Verification of Cryptographic Signature vulnerability, allows attackers to shop for free in merchants\u0027 websites and mobile apps, via a crafted authentication code (MAC) which is generated based on a secret key which is NULL.",
"id": "GHSA-chw7-q7hh-9vc2",
"modified": "2022-07-11T00:00:18Z",
"published": "2022-05-24T17:46:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-23533"
},
{
"type": "WEB",
"url": "https://cwe.mitre.org/data/definitions/347.html"
},
{
"type": "WEB",
"url": "https://www.dropbox.com/s/6smwnbrp0kgsgrc/poc_code.py?dl=0"
},
{
"type": "WEB",
"url": "https://www.dropbox.com/s/czbkdr73tclq2nr/UnionPay_Vulnerability_Report.txt?dl=0"
},
{
"type": "WEB",
"url": "http://mobitec.ie.cuhk.edu.hk/cve_2020"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-CJ56-5C53-9QJF
Vulnerability from github – Published: 2026-06-25 18:30 – Updated: 2026-06-26 18:33wolfSSL_PKCS7_verify() returning success for a degenerate (certs-only) PKCS#7 object that contains no signer. Such an object has empty signerInfos, so the underlying signed-data verification succeeds without authenticating any content. The compatibility-layer verify path now rejects the object when no signer signature has actually been verified, so a PKCS#7 carrying no valid signature is no longer reported as verified. This is enforced regardless of the PKCS7_NOVERIFY flag, which only suppresses signer certificate chain validation and was never intended to waive the requirement that a signature exist. Only affects OpenSSL compatibility builds that call the PKCS7_verify() compatibility API on potentially degenerate PKCS#7 bundles.
{
"affected": [],
"aliases": [
"CVE-2026-55961"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-25T18:16:41Z",
"severity": "HIGH"
},
"details": "wolfSSL_PKCS7_verify() returning success for a degenerate (certs-only) PKCS#7 object that contains no signer. Such an object has empty signerInfos, so the underlying signed-data verification succeeds without authenticating any content. The compatibility-layer verify path now rejects the object when no signer signature has actually been verified, so a PKCS#7 carrying no valid signature is no longer reported as verified. This is enforced regardless of the PKCS7_NOVERIFY flag, which only suppresses signer certificate chain validation and was never intended to waive the requirement that a signature exist. Only affects OpenSSL compatibility builds that call the PKCS7_verify() compatibility API on potentially degenerate PKCS#7 bundles.",
"id": "GHSA-cj56-5c53-9qjf",
"modified": "2026-06-26T18:33:49Z",
"published": "2026-06-25T18:30:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55961"
},
{
"type": "WEB",
"url": "https://github.com/wolfSSL/wolfssl/pull/10702"
},
{
"type": "WEB",
"url": "https://www.wolfssl.com/docs/security-vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-CM49-FH74-75CH
Vulnerability from github – Published: 2022-11-10 12:01 – Updated: 2022-11-23 15:30Insufficient verification of multiple header signatures while loading a Trusted Application (TA) may allow an attacker with privileges to gain code execution in that TA or the OS/kernel.
{
"affected": [],
"aliases": [
"CVE-2021-26391"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-11-09T21:15:00Z",
"severity": "HIGH"
},
"details": "Insufficient verification of multiple header signatures while loading a Trusted Application (TA) may allow an attacker with privileges to gain code execution in that TA or the OS/kernel.",
"id": "GHSA-cm49-fh74-75ch",
"modified": "2022-11-23T15:30:22Z",
"published": "2022-11-10T12:01:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-26391"
},
{
"type": "WEB",
"url": "https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1029"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CMJG-6Q27-6FR4
Vulnerability from github – Published: 2026-07-07 12:31 – Updated: 2026-07-07 12:31Improper verification of cryptographic signature vulnerability in HAVELSAN Inc. Liman MYS allows Fake the Source of Data.
This issue affects Liman MYS: before release.Master.1107.
{
"affected": [],
"aliases": [
"CVE-2026-11348"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-07T12:16:28Z",
"severity": "HIGH"
},
"details": "Improper verification of cryptographic signature vulnerability in HAVELSAN Inc. Liman MYS allows Fake the Source of Data.\n\nThis issue affects Liman MYS: before release.Master.1107.",
"id": "GHSA-cmjg-6q27-6fr4",
"modified": "2026-07-07T12:31:36Z",
"published": "2026-07-07T12:31:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11348"
},
{
"type": "WEB",
"url": "https://siberguvenlik.gov.tr/guvenlik-bildirimleri/detay/tr-26-0504"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CP57-FQ8G-QH6V
Vulnerability from github – Published: 2026-03-26 18:00 – Updated: 2026-03-26 18:00The ML-DSA verification algorithm as specified in FIPS 204, subsection 6.3 requires verifiers to check that the infinity norm of the deserialized signer response $z$ does not exceed $\gamma_1 - \beta$ (line 13 of Algorithm 8). The same check is required to be performed during signature generation.
libcrux-ml-dsa did not perform this check correctly during signature verification, accepting signatures with signer response norm above the allowed maximum value. The check is correctly performed during signing.
Impact
Applications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.
Mitigation
Starting from version 0.0.8, signature verification uses the correct value for $\gamma_1$ in the signer response norm check.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "libcrux-ml-dsa"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-26T18:00:28Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "The ML-DSA verification algorithm as specified in [FIPS 204, subsection 6.3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#subsection.6.3) requires verifiers to check that the infinity norm of the deserialized signer response $z$ does not exceed $\\gamma_1 - \\beta$ (line 13 of Algorithm 8). The same check is required to be performed during signature generation.\n\nlibcrux-ml-dsa did not perform this check correctly during signature verification, accepting signatures with signer response norm above the allowed maximum value. The check is correctly performed during signing.\n\n## Impact\nApplications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.\n\n## Mitigation\nStarting from version `0.0.8`, signature verification uses the correct value for $\\gamma_1$ in the signer response norm check.",
"id": "GHSA-cp57-fq8g-qh6v",
"modified": "2026-03-26T18:00:28Z",
"published": "2026-03-26T18:00:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/cryspen/libcrux/pull/1347"
},
{
"type": "PACKAGE",
"url": "https://github.com/cryspen/libcrux"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0077.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "libcrux has an Incorrect Check of Signer Response Norm During Verification"
}
GHSA-CPPW-2MF8-QPM5
Vulnerability from github – Published: 2022-05-24 22:01 – Updated: 2024-09-24 15:48Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "matrix-synapse"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-18835"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2022-09-19T19:32:08Z",
"nvd_published_at": "2019-11-08T00:15:00Z",
"severity": "HIGH"
},
"details": "Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over `/send_join`, `/send_leave`, and `/invite` may not be correctly signed, or may not come from the expected servers.",
"id": "GHSA-cppw-2mf8-qpm5",
"modified": "2024-09-24T15:48:55Z",
"published": "2022-05-24T22:01:05Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-18835"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/pull/6262"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/commit/172f264ed38e8bef857552f93114b4ee113a880b"
},
{
"type": "PACKAGE",
"url": "https://github.com/matrix-org/synapse"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/releases/tag/v1.5.0"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2019-186.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Improper Verification of Cryptographic Signature in matrix-synapse"
}
GHSA-CPW3-5JQ9-5GF5
Vulnerability from github – Published: 2026-09-01 21:31 – Updated: 2026-09-04 15:36A signature verification bypass vulnerability exists in the command line interface of AOS-CX. Successful exploitation could allow an authenticated malicious actor with administrative privileges to execute arbitrary code on the underlying operating system, when certain pre-conditions outside of the attacker’s control are met.
{
"affected": [],
"aliases": [
"CVE-2026-73776"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-01T21:18:44Z",
"severity": "HIGH"
},
"details": "A signature verification bypass vulnerability exists in the command line interface of AOS-CX. Successful exploitation could allow an authenticated malicious actor with administrative privileges to execute arbitrary code on the underlying operating system, when certain pre-conditions outside of the attacker\u00e2\u20ac\u2122s control are met.",
"id": "GHSA-cpw3-5jq9-5gf5",
"modified": "2026-09-04T15:36:01Z",
"published": "2026-09-01T21:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73776"
},
{
"type": "WEB",
"url": "https://support.hpe.com/hpesc/public/docDisplay?docId=hpesbnw05134en_us\u0026docLocale=en_US"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-CQ44-X9VF-FPQG
Vulnerability from github – Published: 2026-09-05 21:31 – Updated: 2026-09-17 15:31MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use the root’s public certificate - without its private key - to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation.
This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
{
"affected": [],
"aliases": [
"CVE-2026-67278"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-05T20:17:18Z",
"severity": "MODERATE"
},
"details": "MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use the root\u2019s public certificate - without its private key - to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation.\n\nThis issue was fixed in versions:\u00a06.49.21 (Long-term),\u00a07.23.4 (Long-term)\u00a0and\u00a07.24.2 (Stable)",
"id": "GHSA-cq44-x9vf-fpqg",
"modified": "2026-09-17T15:31:32Z",
"published": "2026-09-05T21:31:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-67278"
},
{
"type": "WEB",
"url": "https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve"
},
{
"type": "WEB",
"url": "https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited"
},
{
"type": "WEB",
"url": "https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802"
},
{
"type": "WEB",
"url": "https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801"
},
{
"type": "WEB",
"url": "https://forum.mikrotik.com/t/7-23-6-long-term-is-released/273139"
},
{
"type": "WEB",
"url": "https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800"
},
{
"type": "WEB",
"url": "https://forum.mikrotik.com/t/7-24-3-stable-is-released/273138"
},
{
"type": "WEB",
"url": "https://mikrotik.com/supportsec/september-2026-vulnerability"
},
{
"type": "WEB",
"url": "https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-CQGF-G3QQ-HHXW
Vulnerability from github – Published: 2023-11-14 21:31 – Updated: 2025-02-13 18:32Improper signature verification of RadeonTM RX Vega M Graphics driver for Windows may allow an attacker with admin privileges to launch RadeonInstaller.exe without validating the file signature potentially leading to arbitrary code execution.
{
"affected": [],
"aliases": [
"CVE-2023-20568"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-11-14T19:15:15Z",
"severity": "MODERATE"
},
"details": "Improper signature verification of RadeonTM RX Vega M Graphics driver for Windows may allow an attacker with admin privileges to launch RadeonInstaller.exe without validating the file signature potentially leading to arbitrary code execution.",
"id": "GHSA-cqgf-g3qq-hhxw",
"modified": "2025-02-13T18:32:03Z",
"published": "2023-11-14T21:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-20568"
},
{
"type": "WEB",
"url": "https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-6003"
},
{
"type": "WEB",
"url": "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00971.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
No mitigation information available for this CWE.
CAPEC-463: Padding Oracle Crypto Attack
An adversary is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an adversary is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an adversary is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key.
CAPEC-475: Signature Spoofing by Improper Validation
An adversary exploits a cryptographic weakness in the signature verification algorithm implementation to generate a valid signature without knowing the key.