CVE-2025-20773: 
NixOS vulnerability analysis and mitigation

CVE-2025-20773 is a use-after-free memory corruption vulnerability in the display component of MediaTek chipsets affecting Android devices. A malicious actor who has already obtained System-level privileges can exploit this flaw to further escalate local privileges without any user interaction. The vulnerability affects Android versions 14.0, 15.0, and 16.0 running on a broad range of MediaTek chipsets (MT2718, MT6739, MT6761, MT6765, MT6768, MT6781, MT6789, MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879, MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT8196, MT8676, MT8678, MT8792, MT8793). It was published on December 2, 2025, with a patch released in MediaTek's December 2025 Product Security Bulletin. The CVSS v3.1 base score is 6.7 (Medium) (MediaTek Bulletin, Red Hat CVE).

The vulnerability is classified under CWE-416 (Use After Free) and CWE-415 (Double Free), rooted in improper memory management within the MediaTek display driver component. After a memory object is freed, a reference to it can still be used, leading to memory corruption that an attacker with System privileges can leverage to gain further elevated access. Exploitation requires local access and existing System-level privileges (high privilege precondition), but no user interaction is needed. The patch is identified as Patch ID: ALPS10196993, Issue ID: MSV-4797 (MediaTek Bulletin).

Successful exploitation allows an attacker who already holds System-level privileges to escalate further locally, with high impact on confidentiality, integrity, and availability of the affected device. This could enable an attacker to access sensitive data, modify system state, or cause denial of service on the compromised Android device. The scope is limited to the affected device (unchanged scope), but the breadth of affected MediaTek chipsets means a large number of Android 14, 15, and 16 devices are potentially at risk (MediaTek Bulletin, Red Hat CVE).

There is no public proof-of-concept exploit available, and no evidence of in-the-wild exploitation has been observed as of the time of reporting. The EPSS score is approximately 0.018% (0.000180), indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires the attacker to have already obtained System-level privileges on the target device, which significantly limits the practical attack surface (MediaTek Bulletin).

MediaTek has released a patch (Patch ID: ALPS10196993) addressing this vulnerability, included in the December 2025 MediaTek Product Security Bulletin for Android 14.0, 15.0, and 16.0. Device manufacturers and OEMs should integrate and distribute this patch to affected devices promptly. Lenovo has also issued a security advisory for affected MediaTek-based tablets. As interim measures, organizations should limit System-level access to trusted users and monitor for unauthorized privilege escalation attempts (MediaTek Bulletin, Lenovo Advisory).