CVE-2020-0256: 
NixOS vulnerability analysis and mitigation

An out-of-bounds write vulnerability was discovered in the LoadPartitionTable function of gpt.cc (CVE-2020-0256). The vulnerability affects Android versions 8.0, 8.1, 9, and 10, as well as various Linux distributions using the gdisk package. The issue was disclosed in August 2020 and stems from a missing bounds check in the code (CVE Details, Debian Security).

The vulnerability is characterized by an out-of-bounds write condition in the LoadPartitionTable function of gpt.cc, caused by insufficient bounds checking. The vulnerability has been assigned a CVSS 3.1 base score of 6.8 (Medium), with the following vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. The attack vector is physical, requiring low attack complexity, no privileges, and no user interaction (Ubuntu Security).

The vulnerability can lead to local privilege escalation when a malicious USB device is inserted into the system. The impact is significant as it affects confidentiality, integrity, and availability with high severity ratings. No additional execution privileges are needed for exploitation, and user interaction is not required (CVE Mitre).

The vulnerability can be exploited by inserting a malicious USB device containing a specially crafted GPT table. No additional execution privileges or user interaction is required for successful exploitation (Debian LTS).

Multiple vendors have released patches to address this vulnerability. Debian released version 1.0.1-1+deb9u1 for Stretch, Ubuntu provided fixes through version 1.0.1-1ubuntu0.1~esm2 for Ubuntu 16.04 LTS, and fixes are available through Ubuntu Pro and Ubuntu Pro (Infra-only) via ESM Infra (Debian LTS, Ubuntu Security).