CVE-2020-35493: 
NixOS vulnerability analysis and mitigation

A heap buffer overflow vulnerability (CVE-2020-35493) was discovered in GNU Binutils versions prior to 2.34, specifically in the bfd/pef.c file. The vulnerability was identified in the bfd_pef_parse_function_stubs function when parsing PEF (Preferred Executable Format) files using the objdump utility (Red Hat Bugzilla, NVD).

The vulnerability stems from an improper length check in the bfd_pef_parse_function_stubs function within bfd/pef.c. While there is a length check for 'if ((codepos + 4) > codelen)', the subsequent call to bfd_pef_parse_function_stub() passes in length 24, which could potentially read past the end of the codebuf buffer. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 (Medium) with the vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H (Red Hat Bugzilla, NetApp Advisory).

When successfully exploited, this vulnerability could lead to an out-of-bounds read that results in a denial of service condition, impacting application availability. The vulnerability requires user interaction to process a specially crafted PEF file (NVD, NetApp Advisory).

The vulnerability requires local access and user interaction to exploit. An attacker would need to submit a specially crafted PEF file to be parsed by objdump to trigger the heap buffer overflow condition (Red Hat Bugzilla).

The vulnerability was fixed in GNU Binutils version 2.34 and later. Users are advised to upgrade to the patched version. The fix was implemented through a patch that can be found in the upstream commit (Red Hat Bugzilla, Gentoo Advisory).