CVE-2023-36456
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 · uneditedauthentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used. This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to. Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
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 analysisA detailed technical summary for this CVE is being prepared.
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< 2023.4.3>= 2023.5.0, < 2023.5.5CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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 · scoped2023.4.32023.5.5
2023.4.3 (for versions < 2023.5.0) or 2023.5.5 (for versions >= 2023.5.0)
- If currently running version < 2023.5.0, upgrade to version 2023.4.3 or later
- If currently running version >= 2023.5.0 and < 2023.5.5, upgrade to version 2023.5.5 or later
- After upgrade, verify that IP address handling now validates X-Forwarded-For and X-Real-IP headers properly (header is only trusted from trusted reverse proxies)
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-36456 — 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-2023-36456 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data