Medium
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2019-3877
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 12:28 UTC · Revision 1
Source evidence
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.
osv:CVE-2019-3877
Complete source record
{
"id": "4db0d2ced04349eadf65556e74e55a40fc45893fdece6457b214a1ab1de6024c",
"url": "https://osv.dev/vulnerability/CVE-2019-3877",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2019-3877",
"summary": "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.",
"evidence": "osv:CVE-2019-3877",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2019-3877",
"aliases": [
"CVE-2019-3877"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/uninett/mod_auth_mellon",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "7d681177cb23253e1136afd18cb1916f3865554e"
},
{
"fixed": "62041428a32de402e0be6ba45fe12df6a83bedb8"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mod_auth_mellon_project:mod_auth_mellon:*:*:*:*:*:apache:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "0.14.2"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "62041428a32de402e0be6ba45fe12df6a83bedb8"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"v0.14.1",
"v0.14.0",
"v0.13.1",
"v0.13.0",
"v0.12.0",
"v0.11.0",
"v0.10.0",
"v0.8.0",
"v0.9.1",
"v0.9.0",
"v0.7.0",
"v0.6.1",
"v0.6.0",
"v0.6.0-rc1",
"v0.5.0",
"v0.4.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-3877.json",
"vanir_signatures": [
{
"id": "CVE-2019-3877-2744b448",
"digest": {
"threshold": 0.9,
"line_hashes": [
"32044419064285296566063656658415165029",
"21061309776983139534989088880159912311",
"28373241189536936529294675472970530512",
"210226503878164329466142730749373246164"
]
},
"source": "https://github.com/uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8",
"target": {
"file": "auth_mellon_util.c"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2019-3877-f30d3048",
"digest": {
"length": 298,
"function_hash": "279795152569979611241225697117366206789"
},
"source": "https://github.com/uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8",
"target": {
"file": "auth_mellon_util.c",
"function": "am_check_url"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
}
],
"vanir_signatures_modified": "2026-10-20T13:41:50Z"
}
}
],
"modified": "2026-10-20T13:41:50.703421963Z",
"provider": "osv",
"references": [
"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://access.redhat.com/errata/RHSA-2019:0766",
"https://access.redhat.com/errata/RHSA-2019:3421",
"https://usn.ubuntu.com/3924-1/",
"https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3877",
"https://github.com/Uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8",
"https://github.com/Uninett/mod_auth_mellon/issues/35"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "18.04"
},
{
"last_affected": "18.04"
},
{
"introduced": "18.10"
},
{
"last_affected": "18.10"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "29"
},
{
"last_affected": "29"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*"
],
"vendor_product": "redhat:enterprise_linux",
"extracted_events": [
{
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2019-3877",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 387969,
"published_at": "2019-03-27T13:29:01.82+00:00"
}