ubuntu-cve-2025-48994
Vulnerability from osv_ubuntu
Published
2025-06-02 17:15
Modified
2026-05-20 15:22
Summary
Details

SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (signxml.XMLVerifier.verify(require_x509=False, hmac_key=...), versions of SignXML prior to 4.0.4 are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the signxml.XMLVerifier.verify(expect_config=...) setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying hmac_key causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-signxml",
            "binary_version": "4.0.5+dfsg-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "python-signxml",
        "purl": "pkg:deb/ubuntu/python-signxml@4.0.5+dfsg-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.3+dfsg-1",
        "4.0.5+dfsg-1",
        "4.0.5+dfsg-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-signxml",
            "binary_version": "4.2.0+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "python-signxml",
        "purl": "pkg:deb/ubuntu/python-signxml@4.2.0+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.5+dfsg-2",
        "4.2.0+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), versions of SignXML prior to 4.0.4 are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.",
  "id": "UBUNTU-CVE-2025-48994",
  "modified": "2026-05-20T15:22:53Z",
  "published": "2025-06-02T17:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-48994"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-48994"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/XML-Security/signxml/security/advisories/GHSA-6vx8-pcwv-xhf4"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/XML-Security/signxml/commit/e3c0c2b82a3329a65d917830657649c98b8c7600"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-48994"
  ]
}



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