GHSA-xrw9-r35x-x878
Zitadel allows brute-forcing authentication factors
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/zitadel/zitadel/v2🐹github.com/zitadel/zitadelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A vulnerability in Zitadel allowed brute-force attack on OTP, TOTP and password allowing to impersonate the attacked user.
Impact
An attacker can perform an online brute-force attack on OTP, TOTP, and passwords. While Zitadel allows preventing online brute force attacks in scenarios like TOTP, Email OTP, or passwords using a lockout mechanism. The mechanism is not enabled by default and can cause a denial of service for the corresponding user if enabled. Additionally, the mitigation strategies were not fully implemented in the more recent resource-based APIs.
Affected Versions
All versions within the following ranges, including release candidates (RCs), are affected:
- 4.x:
4.0.0to4.4.0(including RC versions) - 3.x:
3.0.0to3.4.2(including RC versions) - 2.x:
v2.0.0to2.71.17
Patches
The vulnerability has been addressed in the latest releases. The patch resolves the issue by enforcing the lockout policy on all OTP, TOTP and password checks. Additionally a “tar pit” has been introduced to slow down brute-force attacks by default. Zitadel responses will be delayed by t seconds, where t increases over the number of failed attempts within a given timeframe.
4.x: Upgrade to >=4.6.0 3.x: Update to >=3.4.3 2.x: Update to >=2.71.18
Workarounds
The recommended solution is to update Zitadel to a patched version.
The problem might be mitigated by enabling the optional logout policy ("Password maximum attempts") or by implementing more strict rate limits.
Questions
If you have any questions or comments about this advisory, please email us at [email protected]
Credits
This vulnerability was found by zentrust partners GmbH during a scheduled penetration test. Thank you to the analysts Martin Tschirsich, Joud Zakharia, Christopher Baumann. The full report will be made public after the complete review.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/zitadel/zitadel/v2 | all versions | 2.71.18 |
| 🐹Go | github.com/zitadel/zitadel | all versions | 1.80.0-v2.20.0.20251029090735-b8db8cdf9cc8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/zitadel/zitadel/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/zitadel/zitadel/v2 to 2.71.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xrw9-r35x-x878 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xrw9-r35x-x878 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xrw9-r35x-x878. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xrw9-r35x-x878 in your dependencies?
O3 detects GHSA-xrw9-r35x-x878 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.