Description
mod_auth_mellon through 0.14.2 has an Open Redirect via the login?ReturnTo= substring, as demonstrated by omitting the // after http: in the target URL.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libapache2-mod-auth-mellon | 0.15.0-1 | — |
| Debian 13 | libapache2-mod-auth-mellon | 0.15.0-1 | — |
| Debian 12 | libapache2-mod-auth-mellon | 0.15.0-1 | — |
| Debian 10 | libapache2-mod-auth-mellon | 0.14.2-1+deb10u1 | DLA-3359-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libapache2-mod-auth-mellon | 0.14.2-1ubuntu2 | — |
| Ubuntu 18.04 LTS | libapache2-mod-auth-mellon | 0.13.1-1ubuntu0.2 | USN-4291-1 |
| Ubuntu 16.04 LTS | libapache2-mod-auth-mellon | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | mod_auth_mellon +1 | 0.14.0-11.el8 | RHSA-2020:1660 |
| RHEL 7 | mod_auth_mellon +1 | 0.14.0-8.el7 | RHSA-2020:1003 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | mod_auth_mellon +1 | 0.14.0-8.amzn2 | ALAS2-2020-1436 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | mod_auth_mellon +1 | 0.14.0-11.el8 | ELSA-2020-1660 |
| Oracle Linux 7 | mod_auth_mellon +1 | 0.14.0-8.el7 | ELSA-2020-1003 |
Advisories 8
- RHSA-2020:1003 Red Hat Security Advisory: mod_auth_mellon security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4291-1 libapache2-mod-auth-mellon vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-3359-1 libapache2-mod-auth-mellon - security update Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2025-2548 Red Hat Enterprise Linux: Mehrere Schwachstellen BSI CERT-Bund (WID) · Dec 2, 2025
- RHSA-2020:1660 Red Hat Security Advisory: mod_auth_mellon security and bug fix update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- ALAS2-2020-1436 Moderate: mod_auth_mellon security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 17, 2020
- ELSA-2020-1660 Moderate: mod_auth_mellon security and bug fix update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 5, 2020
- ELSA-2020-1003 Moderate: mod_auth_mellon security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 6, 2020
References
- FEDORA-2019-e8d74ece30 vendor-advisory
- FEDORA-2019-1444823e77 vendor-advisory
- USN-4291-1 vendor-advisory
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://github.com/Uninett/mod_auth_mellon/issues/35#issuecomment-503974885
- [debian-lts-announce] 20230312 [SECURITY] [DLA 3359-1] libapache2-mod-auth-mellon security update mailing-list