CVE-2019-3877

Name: CVE-2019-3877
Creator: NVD / NIST
Published: 2019-03-27T13:29:01.82+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.13%

Last modified Jun 17, 2026

CVE-2019-3877 is a vulnerability of currently unknown severity. A vulnerability was found in mod_auth_mellon before v0.14.2. 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. EPSS estimates a 2.13% chance of exploitation in the next 30 days.

Description

A vulnerability was found in mod_auth_mellon before v0.14.2. 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.

Metrics

EPSS Probability

2.13%

79.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mod Auth Mellon Project	Mod Auth Mellon	< 0.14.2
Fedoraproject	Fedora	29
Redhat	Enterprise Linux	7.0
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10

References

https://access.redhat.com/errata/RHSA-2019:0766
https://access.redhat.com/errata/RHSA-2019:3421
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3877Issue Tracking, Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/issues/35Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/
https://usn.ubuntu.com/3924-1/Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0766
https://access.redhat.com/errata/RHSA-2019:3421
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3877Issue Tracking, Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/issues/35Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/
https://usn.ubuntu.com/3924-1/Third Party Advisory

Timeline

Published: Mar 27, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-3877?

How severe is CVE-2019-3877?

Severity scoring for CVE-2019-3877 is pending analysis. The EPSS model estimates a 2.13% probability of exploitation in the next 30 days.

How do I fix CVE-2019-3877?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-3877?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST