GHSA-5684-g483-2249 Signature Validation Bypass
Attackers can bypass SAML signature validation to access unauthorized accounts or achieve full authentication bypass in applications using the gosaml2 library.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-5684-g483-2249?
GHSA-5684-g483-2249 is an authentication bypass vulnerability in github.com/russellhaering/gosaml2, published on 24 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Impact
Given a valid SAML Response, an attacker can potentially modify the document, bypassing signature validation in order to pass off the altered document as a signed one.
This enables a variety of attacks, including users accessing accounts other than the one to which they authenticated in the identity provider, or full authentication bypass if an external attacker can obtain an expired, signed SAML Response.
Patches
A patch is available, users of gosaml2 should upgrade to v0.5.0 or higher.
References
See the underlying advisory on goxmldsig for more details.
Which versions are affected by GHSA-5684-g483-2249?
2 open source packages ship an affected version, including github.com/russellhaering/gosaml2.
| Package | Affected | Fixed in |
|---|---|---|
github.com/russellhaering/gosaml2 Go | All versions | 0.5.0 |
github.com/russellhaering/gosaml2 Go | All versions | 0.5.0 |
How do I fix GHSA-5684-g483-2249?
Upgrade github.com/russellhaering/gosaml2 to 0.5.0 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is GHSA-5684-g483-2249 being exploited?
There is no known exploitation of GHSA-5684-g483-2249 in the wild and no public exploit code.