CVE-2021-31348: 
Linux Debian vulnerability analysis and mitigation

An issue was discovered in libezxml.a in ezXML 0.8.6. The function ezxml_parse_str() performs incorrect memory handling while parsing crafted XML files, leading to an out-of-bounds read after a certain strcspn failure (NVD, Ubuntu).

The vulnerability occurs in the ezxml_parse_str() function when processing XML files. The issue arises when strcspn(s + 1, "[]>") + 1 does not find any of the []> characters in the input string, causing the pointer to move beyond the allocated buffer boundaries. This results in an out-of-bounds read operation. The vulnerability has been assigned a CVSS v3.1 score of 6.5 (Medium) (NVD).

When exploited, this vulnerability can lead to an out-of-bounds read after a strcspn failure, potentially causing application crashes or information disclosure. The issue affects multiple packages that use the ezXML library, including mapcache, netcdf, netcdf-parallel, and scilab (Debian).

The vulnerability can be triggered by processing specially crafted XML files that exploit the incorrect memory handling in the ezxml_parse_str() function. The issue requires user interaction to process a malicious XML file (Ubuntu).

Several distributions have released patches to address this vulnerability. For Debian 9 (stretch), the fix was included in scilab version 5.5.2-4+deb9u1. Various Ubuntu releases have also received updates, with some versions being marked as "not affected" in newer releases (Debian LTS).