CVE-2021-25481

Vulnerability

An improper error handling vulnerability exists in the Exynos CP (Communication Processor) booting driver on Samsung mobile devices. This allows a local attacker to bypass the Secure Memory Protector of Exynos CP Memory. The issue affects devices prior to the SMR Oct-2021 Release 1, which corresponds to the October 2021 Security Maintenance Release. The vulnerable code path is reachable by an attacker with local access to the device.

Exploitation

An attacker needs local access to the affected device to exploit this vulnerability. No user interaction or special privileges beyond local access are explicitly required. The attacker can trigger the improper error handling in the Exynos CP booting driver to bypass the Secure Memory Protector. The exact sequence of steps is not detailed in available references [1].

Impact

Successful exploitation allows a local attacker to bypass the Secure Memory Protector of Exynos CP Memory. This compromises the confidentiality and integrity of data protected by that mechanism, potentially exposing sensitive information processed by the cellular modem or allowing unauthorized modifications to CP memory.

Mitigation

The vulnerability is fixed in the Samsung Mobile Security Update SMR Oct-2021 Release 1. Users should apply the latest security update provided by Samsung via their device settings or manufacturer updates. No other workarounds are disclosed in the available references [1].