Important: mod_auth_mellon

Issue Overview:

A vulnerability was found in a previous version of mod_auth_mellon. An open redirect in the logout URL allows requests with backslashes to pass through by assuming that it is a relative URL, while the browsers silently convert backslash characters into forward slashes treating them as an absolute URL. This mismatch allows an attacker to bypass the redirect URL validation logic in apr_uri_parse function.(CVE-2019-3877)

A vulnerability was found in mod_auth_mellon. If Apache is configured as a reverse proxy and mod_auth_mellon is configured to only let through authenticated users (with the require valid-user directive), adding special HTTP headers that are normally used to start the special SAML ECP (non-browser based) can be used to bypass authentication.(CVE-2019-3878)

Affected Packages:

mod_auth_mellon

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update mod_auth_mellon to update your system.

New Packages:

aarch64:  
    mod_auth_mellon-0.14.0-2.amzn2.4.aarch64  
    mod_auth_mellon-debuginfo-0.14.0-2.amzn2.4.aarch64  
    mod_auth_mellon-diagnostics-0.14.0-2.amzn2.4.aarch64  
  
i686:  
    mod_auth_mellon-0.14.0-2.amzn2.4.i686  
    mod_auth_mellon-debuginfo-0.14.0-2.amzn2.4.i686  
    mod_auth_mellon-diagnostics-0.14.0-2.amzn2.4.i686  
  
src:  
    mod_auth_mellon-0.14.0-2.amzn2.4.src  
  
x86_64:  
    mod_auth_mellon-0.14.0-2.amzn2.4.x86_64  
    mod_auth_mellon-debuginfo-0.14.0-2.amzn2.4.x86_64  
    mod_auth_mellon-diagnostics-0.14.0-2.amzn2.4.x86_64  

Additional References

Red Hat: CVE-2019-3877, CVE-2019-3878

Mitre: CVE-2019-3877, CVE-2019-3878