CVE-2020-21528: 
Linux Debian vulnerability analysis and mitigation

A Segmentation Fault vulnerability (CVE-2020-21528) was discovered in the ieee_segment function in outieee.c in NASM (Netwide Assembler) versions 2.14.03 and 2.15. The vulnerability was reported in December 2019 and was officially published in the NVD database on August 22, 2023 (NIST NVD).

The vulnerability exists in the ieee_segment function within outieee.c file at line 705:18. When processing certain crafted assembly files, the function attempts to perform a string comparison operation on an invalid memory address, resulting in a segmentation fault. The vulnerability has a CVSS v3.1 base score of 5.5 MEDIUM with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H (NIST NVD).

The vulnerability allows remote attackers to cause a denial of service condition via a specially crafted assembly file. When exploited, the application crashes due to the segmentation fault, disrupting the assembly process (NIST NVD).

The vulnerability has been fixed in NASM version 2.16.01. Users should upgrade to this version or later to address the issue. The fix was implemented in commit 93c774d482694643cafbc82578ac8b729fb5bc8b (Nasm Bugzilla, Gentoo Advisory).