CyberSecBulletin
CVE-2025-64102NVD status: Analyzed

zitadel: Improper Restriction of Excessive Authentication Attempts

Published Updated By the CyberSecBulletin desk

CVE-2025-64102 is a critical-severity improper restriction of excessive authentication attempts vulnerability in zitadel, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected zitadel versions: >= 4.0.0-rc.1, < 4.6.0; >= 3.0.0-rc.1, < 3.4.3; >= 2.0.0, < 2.71.18. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of zitadel you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Zitadelzitadel>= 4.0.0-rc.1, < 4.6.0; >= 3.0.0-rc.1, < 3.4.3; >= 2.0.0, < 2.71.18Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.07.7HighCNA (github.com)
CVSS 3.19.8CriticalNVD

Official description

Zitadel is open-source identity infrastructure software. Prior to 4.6.0, 3.4.3, and 2.71.18, 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. This vulnerability is fixed in 4.6.0, 3.4.3, and 2.71.18.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Restriction of Excessive Authentication Attempts

The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.

How developers prevent this class of flaw

  • Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.

More Improper Restriction of Excessive Authentication Attempts vulnerabilities (CWE-307)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in zitadel

All zitadel vulnerabilities

Recent Improper Restriction of Excessive Authentication Attempts vulnerabilities

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