CVE-2023-45683: Cross site scripting via missing binding syntax validation In ACS location in github.com/crewjam/saml

Vulnerability summary

CVE-2023-45683 is a high (CVSS 7.1) vulnerability in crewjam saml. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 41.7% of scored vulnerabilities.

Timeline

1. 16-10-2023
   PublishedVulnerability first disclosed.
2. 13-09-2024
   Last modifiedVulnerability information updated.

Description

github.com/crewjam/saml is a saml library for the go language. In affected versions the package does not validate the ACS Location URI according to the SAML binding being parsed. If abused, this flaw allows attackers to register malicious Service Providers at the IdP and inject Javascript in the ACS endpoint definition, achieving Cross-Site-Scripting (XSS) in the IdP context during the redirection at the end of a SAML SSO Flow. Consequently, an attacker may perform any authenticated action as the victim once the victim’s browser loaded the SAML IdP initiated SSO link for the malicious service provider. Note: SP registration is commonly an unrestricted operation in IdPs, hence not requiring particular permissions or publicly accessible to ease the IdP interoperability. This issue is fixed in version 0.4.14. Users unable to upgrade may perform external validation of URLs provided in SAML metadata, or restrict the ability for end-users to upload arbitrary metadata.

• CWE-79Improper Neutralization of Input During Web Page GenerationThe product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.