Debian LinuxOperating system · Debian
CVE-2022-23527
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedmod_auth_openidc is an OpenID Certified™ authentication and authorization module for the Apache 2.x HTTP server. Versions prior to 2.4.12.2 are vulnerable to Open Redirect. When providing a logout parameter to the redirect URI, the existing code in oidc_validate_redirect_url() does not properly check for URLs that start with /\t, leading to an open redirect. This issue has been patched in version 2.4.12.2. Users unable to upgrade can mitigate the issue by configuring mod_auth_openidc to only allow redirection when the destination matches a given regular expression with OIDCRedirectURLsAllowed.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencemod_auth_openidc versions prior to 2.4.12.2 contain an open redirect vulnerability in oidc_validate_redirect_url(). The function fails to properly validate redirect URLs containing /\t (slash-tab) at the start, allowing attackers to craft malicious logout redirect URLs that bypass validation and direct users to attacker-controlled sites.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Debian LinuxOperating system
= 10.0< 2.4.12.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine installed mod_auth_openidc versionRun 'apachectl -M 2>/dev/null | grep openidc' to confirm the module is loaded, then check the package version with 'dpkg -l libapache2-mod-auth-openidc' (Debian) or 'rpm -qa | grep mod_auth_openidc' (RHEL), or check the file /usr/lib/apache2/modules/mod_auth_openidc.so modification dateAffected if The installed version is lower than 2.4.12.2 or cannot be determined to be 2.4.12.2 or later
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Identify configured OIDCRedirectURLsAllowed directivesSearch Apache configuration files (httpd.conf, include files in /etc/apache2, or virtual host configs) for any 'OIDCRedirectURLsAllowed' directives using 'grep -r OIDCRedirectURLsAllowed /etc/apache2 /etc/httpd'Affected if No OIDCRedirectURLsAllowed directive is present, or the directive allows broad patterns (e.g., '.*' or overly permissive regex) that could be bypassed by the slash-tab sequence
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Check for logout redirect URL configurationsSearch for OIDCLogoutRedirectURLs or similar logout-related directives in Apache configs with 'grep -ri logout /etc/apache2 /etc/httpd'Affected if Logout redirect URLs are configured and could accept user-controlled or external redirect targets without strict validation
You are affected if mod_auth_openidc version is below 2.4.12.2 AND logout redirect functionality is in use without a restrictive OIDCRedirectURLsAllowed configuration that explicitly prevents the slash-tab bypass.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.4.12.2
Upgrade to mod_auth_openidc version 2.4.12.2 or later. Alternatively, if upgrading is not possible, configure OIDCRedirectURLsAllowed with a restrictive regex pattern to limit allowed redirect destinations.
mod_auth_openidc version 2.4.12.2
- Upgrade mod_auth_openidc to version 2.4.12.2 or later to resolve the Open Redirect vulnerability in oidc_validate_redirect_url()
- If upgrading is not immediately possible, add or update the OIDCRedirectURLsAllowed directive in the Apache configuration to restrict redirection destinations to a specific regular expression pattern
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-23527 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-23527 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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