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Not in CISA KEV
HIGH severity

GHSA-ffhg-7mh4-33c4

HIGHFix: golang/crypto@bac4c82

GHSA-ffhg-7mh4-33c4 is a high-severity (CVSS 7.5) CWE-347 vulnerability in golang.org/x/crypto. 4 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-ffhg-7mh4-33c4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Improper Verification of Cryptographic Signature in golang.org/x/crypto

Also known asCVE-2020-9283GO-2020-0012
Published
May 18, 2021
Updated
Feb 4, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
4 known
Exploitation data as of Feb 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐹golang.org/x/crypto

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

golang.org/x/crypto before v0.0.0-20200220183623-bac4c82f6975 for Go allows a panic during signature verification in the golang.org/x/crypto/ssh package. A client can attack an SSH server that accepts public keys. Also, a server can attack any SSH client.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogolang.org/x/cryptoall versions0.0.0-20200220183623-bac4c82f6975
Exploits & PoCs
4

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-48121doslinux

Go SSH servers 0.0.2 - Denial of Service (PoC)

by Mark Adams · Feb 24, 2020

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/crypto. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update golang.org/x/crypto to 0.0.0-20200220183623-bac4c82f6975 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ffhg-7mh4-33c4 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-ffhg-7mh4-33c4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-ffhg-7mh4-33c4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

OpenShift Container Platform uses the vulnerable library in a number of components but strictly as an SSH client. The severity of this vulnerability is reduced for clients as it requires connections to malicious SSH servers, with the maximum impact only a client crash. This vulnerability is rated Low for OpenShift…

Frequently Asked Questions

golang.org/x/crypto before v0.0.0-20200220183623-bac4c82f6975 for Go allows a panic during signature verification in the golang.org/x/crypto/ssh package. A client can attack an SSH server that accepts public keys. Also, a server can attack any SSH client.
O3 Security · Impact-Aware SCA

Is GHSA-ffhg-7mh4-33c4 in your dependencies?

O3 detects GHSA-ffhg-7mh4-33c4 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-ffhg-7mh4-33c4: crypto (High 7.5) | O3 Security