CVE-2019-20479

A flaw was found in mod_auth_openidc before version 2.4.1. An open redirect issue exists in URLs with a slash and backslash at the beginning.

Published: 2020-02-20 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-20479 is rated Moderate Risk (50.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.57%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-20479

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.63% 1.57% +0.94%
2 2026-05-03 0.49% 0.63% +0.14%
3 2026-01-07 — 0.49% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-20479

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2019-20479

OS Trackers for CVE-2019-20479

vendor priority summary link
debian not yet assigned CVE-2019-20479 not yet assigned priority: Debian including 1 source packages (libapache2-mod-auth-openidc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-20479
redhat medium — https://access.redhat.com/security/cve/CVE-2019-20479
suse medium — https://www.suse.com/security/cve/CVE-2019-20479/
ubuntu medium CVE-2019-20479 medium priority: Ubuntu including 1 source packages (libapache2-mod-auth-openidc), 5 status rows across 5 suites (bionic, eoan, trusty, upstream, xenial): not-affected 3, DNE 1, needs-triage 1. https://ubuntu.com/security/CVE-2019-20479

Affected software / configurations for CVE-2019-20479

Vendor Product Version Raw CPE
openidc mod_auth_openidc < 2.4.1 cpe:2.3:a:openidc:mod_auth_openidc:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

References for CVE-2019-20479

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00036.html Mailing List Third Party Advisory
https://github.com/zmartzone/mod_auth_openidc/commit/02431c0adfa30f478cf2eb20ed6ea51fdf446be7 Patch
https://github.com/zmartzone/mod_auth_openidc/pull/453 Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2020/02/msg00035.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00028.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00034.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/27XJYAEONKJDESNE7WVZF5D2Z2OBY5JK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NGXONXPWTX7DV62TIUIUVOZF4KQ6SIJE/
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