CVE-2020-13649: 
NixOS vulnerability analysis and mitigation

JerryScript version 2.2.0 contains a NULL pointer dereference vulnerability (CVE-2020-13649) in the parser/js/js-scanner.c file. The vulnerability was discovered on May 23, 2020, and affects the error handling during certain out-of-memory conditions, as demonstrated by a scanner_reverse_info_list NULL pointer dereference and a scanner_scan_all assertion failure (MITRE, GitHub Issue).

The vulnerability occurs in the scanner component when handling errors during out-of-memory conditions. Specifically, the issue manifests in two ways: a NULL pointer dereference in the scanner_reverse_info_list function at js-scanner-util.c:1557, and an assertion failure in scanner_scan_all at js-scanner.c:3196. The vulnerability has been assigned a CVSS score of 5.0, indicating medium severity (CISA).

When exploited, this vulnerability can allow attackers to cause a denial of service condition by triggering a NULL pointer dereference, which results in a crash of the application (MITRE).

The vulnerability can be triggered by sending specially crafted input that causes out-of-memory conditions during parsing. A proof-of-concept exploit has been documented that demonstrates how the vulnerability can be triggered using specific JavaScript code patterns (GitHub Issue).

The vulnerability has been fixed in a patch that corrects the error handling in the scanner when dealing with out-of-memory conditions. The fix includes proper validation of memory allocation return values and improved error handling logic (GitHub Commit).