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🐹
🐹 Go
Not in CISA KEV
HIGH severity

CVE-2020-29652 — x/crypto

HIGH

CVE-2020-29652 is a high-severity (CVSS 7.5) NULL Pointer Dereference vulnerability in golang.org/x/crypto. A fix is available for golang.org/x/crypto — see the affected versions and patch details below.

golang.org/x/crypto/ssh NULL Pointer Dereference vulnerability

Also known asGHSA-3vm4-22fp-5rfmGO-2021-0227
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
3.2%probability of exploitation in next 30 days
Lower Risk-0.09%
Lower risk than most CVEs88th percentile — riskier than 88% of all scored CVEsHighest risk
0.00%1.41%2.83%4.24%0.0%3.2%May 26Aug 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

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

A nil pointer dereference in the golang.org/x/crypto/ssh component through v0.0.0-20201203163018-be400aefbc4c for Go allows remote attackers to cause a denial of service against SSH servers. An attacker can craft an authentication request message for the gssapi-with-mic method which will cause NewServerConn to panic via a nil pointer dereference if ServerConfig.GSSAPIWithMICConfig is nil.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogolang.org/x/cryptoall versions0.0.0-20201216223049-8b5274cf687fgo get golang.org/x/crypto@v0.0.0-20201216223049-8b5274cf687f

Affected Products

1 product · 1 configurations
Application
sshgolang
≤ 0.0.0-20201203163018-be400aefbc4c
range

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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update golang.org/x/crypto to 0.0.0-20201216223049-8b5274cf687f or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-29652 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

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

A large number of products include the affected package, but do not make use of the vulnerable SSH server code. Accordingly, the flaw itself is rated as "Important", but these products themselves all have a "Low" severity rating. Additionally, a number of products include golang.org/x/crypto (or even…

ProductFixed inAdvisory
Red Hat Enterprise Linux 8container-tools:rhel8-8040020210407081426.59631bd5RHSA-2021:1796
Red Hat OpenShift Container Platform 4.7openshift4/ose-aws-ebs-csi-driver-rhel8:v4.7.0-202102130115.p0RHSA-2020:5633
RHEL-8-CNV-4.8container-native-virtualization/vm-import-operator-rhel8:v4.8.0-18RHSA-2021:2920

Frequently Asked Questions

A nil pointer dereference in the golang.org/x/crypto/ssh component through v0.0.0-20201203163018-be400aefbc4c for Go allows remote attackers to cause a denial of service against SSH servers. An attacker can craft an authentication request message for the `gssapi-with-mic` method which will cause NewServerConn to panic via a nil pointer dereference if ServerConfig.GSSAPIWithMICConfig is nil.
O3 Security · Impact-Aware SCA

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CVE-2020-29652: x/crypto DoS — Fix Available