Jwt Attack CVE-2025-43521

This vulnerability presents a low-priority remediation target despite a CVSS score of 5.5. Attack vector is local (AV:L), requires no special privileges (PR:N), has low complexity (AC:L), but critically requires user interaction (UI:R) to execute a malicious application. The EPSS score of 0.01% (bottom 1st percentile) indicates near-zero real-world exploitation probability, suggesting either high defense barriers, narrow attacker capability, or both. The information-disclosure-only impact (high confidentiality/no integrity or availability impact) limits blast radius. The vulnerability is not listed as confirmed actively exploited (no CISA KEV status), with no identified public exploit code. This represents a 'high-CVSS-but-low-real-risk' scenario where cryptographic rigor and usability friction significantly reduce practical threat.

An attacker distributes a malicious application (via email, malicious website, or USB drive) that exploits the code-signing downgrade vulnerability. When a user runs this application (satisfying the UI:R requirement), the app leverages the weakness in signature validation to downgrade to legacy or absent cryptographic checks, bypassing macOS Gatekeeper and code-signing protections. Once executed, the application gains local process privileges and reads sensitive user data (browser cookies, cached credentials, application keychain entries, user documents) without triggering security warnings. No public exploit code has been identified, and the extremely low EPSS suggests this attack path faces significant practical obstacles despite technical feasibility.