CVE-2023-28119 — The crewjam/saml go library contains a partial implementation of the SAML standa

The crewjam/saml go library contains a partial implementation of the SAML standard in golang. Prior to version 0.4.13, the package's use of `flate.NewReader` does not limit the size of the input. The user can pass more than 1 MB of data in the HTTP request to the processing

01What is this vulnerability?

The crewjam/saml go library contains a partial implementation of the SAML standard in golang. Prior to version 0.4.13, the package's use of `flate.NewReader` does not limit the size of the input. The user can pass more than 1 MB of data in the HTTP request to the processing functions, which will be decompressed server-side using the Deflate algorithm. Therefore, after repeating the same request…

02Affected products

Vendor	Product	Versions
crewjam	saml	< 0.4.13

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-03-22T19:51:13.210Z
• Last modified: 2025-02-25T14:51:31.420Z

09References

• github.com — https://github.com/crewjam/saml/security/advisories/GHSA-5mqj-xc49-246p
• github.com — https://github.com/crewjam/saml/commit/8e9236867d176ad6338c870a84e2039aef8a5021