CVE-2025-32029: 
JavaScript vulnerability analysis and mitigation

ts-asn1-der, a collection of utility classes for encoding ASN.1 data following DER rules, contains a vulnerability identified as CVE-2025-32029. The vulnerability was discovered and disclosed on April 6, 2025, affecting versions prior to 1.0.4. The issue involves incorrect number DER encoding that can lead to denial of service for absolute values in a specific range (GitHub Advisory).

The vulnerability stems from a flaw in the arithmetic implementation within the numBitLen function. When processing absolute values in the range between 231 and 232 - 1, the function fails to account for potential negative results when applying the right shift (>>) operator. This oversight leads to an infinite loop condition. The vulnerability has been assigned a CVSS v4.0 base score of 6.9 (Medium) with the vector string CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N (GitHub Advisory, NVD).

When exploited, this vulnerability can cause a denial of service condition through an infinite loop when processing certain numeric values. Additionally, the implementation issues result in incorrect value encoding, potentially affecting the integrity of ASN.1 data processing (GitHub Advisory).

The vulnerability has been patched in version 1.0.4 of ts-asn1-der. For users unable to upgrade, a workaround is available by implementing input validation for Asn1Integer to ensure values are within the safe range (not smaller than -231 + 1 and no larger than 231 - 1). Alternatively, input can be provided as a pre-computed DER-encoded buffer, though this requires external DER encoding computation (GitHub Advisory).