CVE-2024-27088: 
JavaScript vulnerability analysis and mitigation

CVE-2024-27088 affects es5-ext, a package containing ECMAScript 5 extensions. The vulnerability was discovered in February 2024 and affects versions from 0.10.0 up to (excluding) 0.10.63. The issue involves a Regular Expression Denial of Service (ReDoS) vulnerability when passing functions with very long names or complex default argument names into function#copy or function#toStringTokens methods (GitHub Advisory).

The vulnerability stems from problematic regex implementation in the function parsing mechanism that is susceptible to excessive backtracking. The regex pattern /^\sfunction\s([\0-')-\uffff]+)\s(([\0-(-\uffff]))\s*{/ can be exploited when there is an imbalance in parentheses, leading to significant CPU load and processing time increases. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 MEDIUM by NVD with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (NVD).

When exploited, this vulnerability can cause the script to stall, potentially leading to a denial of service condition. The impact is primarily on availability, with no direct effect on confidentiality or integrity (GitHub Advisory).

The vulnerability has been patched in version 0.10.63 through commits 3551cdd and a52e957, which implement a more secure approach to function parsing. For users unable to upgrade immediately, the only workaround is to refrain from using the affected utilities function#copy and function#toStringTokens (GitHub Advisory).