A vulnerability was found in mod_auth_mellon before v0.14.2.
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.
- Published
- Mar 27, 2019
- Updated
- Jun 16, 2026
- EPSS
- 2.1% · 81th percentile
- CWE
- CWE-601
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Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 24 / 40 · 6.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
CNA vs NVD score
- NVD
- 6.1
- CNA · redhat
- 5.8
- 0.3 point gap
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| mod auth mellon project | mod auth mellon | cpe:2.3:a:mod_auth_mellon_project:mod_auth_mellon |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux18.04
- canonical ubuntu linux18.10
- fedoraproject fedora29
- mod auth mellon project mod auth mellonbefore 0.14.2
- redhat enterprise linux7.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
uninett mod_auth_mellon
- v0.14.2affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libapache2-mod-auth-mellon | before 0.14.2-1 | 0.14.2-1 |
| Debian:9 | libapache2-mod-auth-mellon | before 0.12.0-2+deb9u1 | 0.12.0-2+deb9u1 |
| Red Hat:enterprise_linux:7::server | mod_auth_mellon | before 0:0.14.0-2.el7_6.4 | 0:0.14.0-2.el7_6.4 |
| Red Hat:enterprise_linux:7::server | mod_auth_mellon-debuginfo | before 0:0.14.0-2.el7_6.4 | 0:0.14.0-2.el7_6.4 |
| Red Hat:enterprise_linux:7::server | mod_auth_mellon-diagnostics | before 0:0.14.0-2.el7_6.4 | 0:0.14.0-2.el7_6.4 |
| Red Hat:enterprise_linux:8::appstream | mod_auth_mellon | before 0:0.14.0-9.el8 | 0:0.14.0-9.el8 |
| Red Hat:enterprise_linux:8::appstream | mod_auth_mellon-debuginfo | before 0:0.14.0-9.el8 | 0:0.14.0-9.el8 |
| Red Hat:enterprise_linux:8::appstream | mod_auth_mellon-debugsource | before 0:0.14.0-9.el8 | 0:0.14.0-9.el8 |
| Red Hat:enterprise_linux:8::appstream | mod_auth_mellon-diagnostics | before 0:0.14.0-9.el8 | 0:0.14.0-9.el8 |
| Red Hat:enterprise_linux:8::appstream | mod_auth_mellon-diagnostics-debuginfo | before 0:0.14.0-9.el8 | 0:0.14.0-9.el8 |
Same product
mod auth mellon project: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-3878A vulnerability was found in mod_auth_mellon before v0.14.2.33Monitor
- CVE-2019-13038mod_auth_mellon through 0.14.2 has an Open Redirect via the login?ReturnTo= substring, as demonstrated by omitting the // after http: in the24Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:libapache2-mod-auth-mellon | 0.14.2-1 · Debian:12 | Package registry (OSV) |
| red hat:mod_auth_mellon | 0:0.14.0-2.el7_6.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:mod_auth_mellon-debuginfo | 0:0.14.0-2.el7_6.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:mod_auth_mellon-debugsource | 0:0.14.0-9.el8 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:mod_auth_mellon-diagnostics | 0:0.14.0-2.el7_6.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:mod_auth_mellon-diagnostics-debuginfo | 0:0.14.0-9.el8 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- access.redhat.com/errata/RHSA-2019:0766
- access.redhat.com/errata/RHSA-2019:3421
- bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3877
- github.com/Uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8
- github.com/Uninett/mod_auth_mellon/issues/35
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/
- usn.ubuntu.com/3924-1/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.