CVE-2020-8827: 
Argo CD vulnerability analysis and mitigation

CVE-2020-8827 is a security vulnerability in Argo CD, a declarative GitOps continuous delivery tool for Kubernetes. The vulnerability relates to insufficient anti-automation and anti-brute force protections in the application's authentication system. This vulnerability was later found to be incompletely fixed, as evidenced by CVE-2024-21662 which undermined the original patch (GitHub Advisory).

The vulnerability is classified as CWE-307 (Improper Restriction of Excessive Authentication Attempts). The issue stems from a weak cache-based mechanism used for brute force protection, which can be bypassed by attackers. The application's brute force protection relies on a cache mechanism that tracks login attempts for each user, with a defaultMaxCacheSize of 1000 entries (GitHub Advisory).

The vulnerability allows attackers to perform unrestricted brute force attacks against user accounts, particularly targeting the default admin account. This could potentially lead to unauthorized access to the Argo CD system and compromise of the entire continuous delivery pipeline (GitHub Advisory).

The vulnerability was addressed through patches released in versions 2.8.13, 2.9.9, and 2.10.4. Users are strongly recommended to upgrade to these versions or later to receive the security fix (GitHub Advisory).