Bypassing Rate Limit and Brute Force Protection Using Cache Overflow

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.4 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS

• CVE-2024-21662: 0.84% estimated exploitation activity in the next 30 days; percentile 57.84 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary An attacker can effectively bypass the rate limit and brute force protections by exploiting the application's weak cache-based mechanism. This loophole in security can be combined with other vulnerabilities to attack the default admin account. This flaw undermines a previously patched CVE intended to protect against brute-force attacks. Details The application's brute force protection relies on a cache mechanism that tracks login attempts for each user. This cache is limited to a defaultMaxCacheSize of 1000 entries. An attacker can overflow this cache by bombarding it with login attempts for different users, thereby pushing out the admin account's failed attempts and effectively resetting the rate limit for that account. The brute force protection mechanism's code: PoC 1. Set up the application environment and identify the login page. 2. Execute 4 failed login attempts for the admin account. 3. Run a Burp Intruder attack to populate the cache with login attempts for usernames…

Published by the source

18 Mar 2024, 20:29 UTC

Last modified by the source

22 Mar 2024, 20:05 UTC

Source last checked

26 Oct 2026, 15:03 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2vgg-9h6w-m454

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# Patch Next advisory brief: CVE-2024-21662

Advisory: Bypassing Rate Limit and Brute Force Protection Using Cache Overflow
IDs: CVE-2024-21662, GHSA-2vgg-9h6w-m454
Record: https://patchnext.com/advisories/cve-2024-21662 (revision 1, source checked 26 Oct 2026, 15:03 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/argoproj/argo-cd/v2 2.10.4, 2.9.9, 2.8.13. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/argoproj/argo-cd/v2: affected < 2.8.13; >= 2.9.0, < 2.9.9; >= 2.10.0, < 2.10.4; fixed in 2.9.9, 2.8.13, 2.10.4

## Suggested inspection (read-only)
- Go github.com/argoproj/argo-cd/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/argoproj/argo-cd/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2vgg-9h6w-m454 (GitHub-reviewed advisory GHSA-2vgg-9h6w-m454 lists affected ranges: Go github.com/argoproj/argo-cd/v2 >=0 =2.9.0 =2.10.0 <2.10.4)

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