Timing Attack Affecting signxml package, versions [,4.0.4)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-PYTHON-SIGNXML-10303872
- published5 Jun 2025
- disclosed2 Jun 2025
- creditahacker1-securesaml
Introduced: 2 Jun 2025
NewCVE-2025-48995 (opens in a new tab)How to fix?
Upgrade signxml to version 4.0.4 or higher.
Overview
signxml is a Python XML Signature and XAdES library
Affected versions of this package are vulnerable to Timing Attack due to the verify function in XMLVerifier. An attacker can infer the correct HMAC used for XML signature verification by observing the time it takes to compare the computed HMAC with the provided hash.
Note: This is only exploitable if X509 certificate validation is turned off and a specific HMAC shared secret is set.