CVE-2019-20581

Vulnerability

A stack overflow vulnerability exists in the HDCP Trustlet on Samsung mobile devices with N(7.x), O(8.x), and P(9.0) software that use Exynos chipsets. The overflow occurs within the Trustlet, a trusted execution environment component handling HDCP (High-bandwidth Digital Content Protection). Affected versions include firmware revisions covered by Samsung's August 2019 security update (SVE-2019-14665) [1].

Exploitation

An attacker needs local access or the ability to execute code within the TrustZone environment to trigger the stack overflow in the HDCP Trustlet. The precise sequence of steps is not disclosed in public references, but the vulnerability is reachable without authentication beyond the device user context [1].

Impact

Successful exploitation leads to arbitrary code execution within the TrustZone trusted execution environment. This allows the attacker to gain elevated privileges, potentially compromising the device's secure world and leading to full disclosure of protected content or device compromise [1].

Mitigation

Samsung addressed this vulnerability in the August 2019 security update. Users should ensure their device is running the latest security patch level. No workaround is available for unpatched devices. The CVE is not listed on CISA's Known Exploited Vulnerabilities (KEV) catalog as of the publication date [1].