CVE-2021-43565: Golang.org/x/crypto X/crypto/ssh Vulnerable To Panic Vulnerability

HIGH
Advisory Identifier: GHSA-gwc9-m7rh-j2ww
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CVSS 7.5
Published
Advisory Summary

CVE-2021-43565 is a HIGH (CVSS 7.5) x/crypto/ssh vulnerable to panic vulnerability (General Security Weakness) affecting Golang.org/x/crypto libraries in the Go ecosystem. The issue involves x/crypto/ssh vulnerable to panic via malformed packets. Remediation is available by upgrading affected packages to version 0.0.0-20211202192323-5770296d904e.

CVE-2021-43565 at a Glance

CVE Identifier CVE-2021-43565
GHSA Identifier GHSA-gwc9-m7rh-j2ww
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification General Security Weakness
Affected Product Golang.org/x/crypto
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-43565

To remediate this vulnerability, upgrade all affected Golang.org/x/crypto dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

golang.org/x/crypto fixed: 0.0.0-20211202192323-5770296d904e 
Upgrade golang.org/x/crypto to 0.0.0-20211202192323-5770296d904e
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for golang.org/x/crypto

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-43565, inspect your project dependencies for Golang.org/x/crypto:

inspect dependencies for golang.org/x/crypto

Analyze the terminal output to locate any version of Golang.org/x/crypto in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20211202192323-5770296d904e), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Golang.org/x/crypto, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The x/crypto/ssh package before 0.0.0-20211202192323-5770296d904e of golang.org/x/crypto allows an unauthenticated attacker to panic an SSH server. When using AES-GCM or ChaCha20Poly1305, consuming a malformed packet which contains an empty plaintext causes a panic.

CVE-2021-43565 Affected Golang.org/x/crypto Versions

1 component(s)
Fixed Versions:
0.0.0-20211202192323-5770296d904e
Product / Package Ecosystem Affected Versions Fixed Version
golang.org/x/crypto
golang/golang.org/x/crypto
Go
< 0.0.0-20211202192323-5770296d904e
0.0.0-20211202192323-5770296d904e

References

NVD — CVE-2021-43565 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-43565
go.dev/cl/368814 WEB
https://go.dev/cl/368814
go.dev/issues/49932 WEB
https://go.dev/issues/49932
groups.google.com/forum/ WEB
https://groups.google.com/forum/#!forum/golang-announce
groups.google.com/g/golang-announce/c... WEB
https://groups.google.com/g/golang-announce/c/2AR1sKiM-Qs
pkg.go.dev/vuln/go-2022-0968 WEB
https://pkg.go.dev/vuln/GO-2022-0968

Frequently Asked Questions

What is CVE-2021-43565?
CVE-2021-43565 is a security vulnerability in Golang.org/x/crypto involving x/crypto/ssh vulnerable to panic via malformed packets under General Security Weakness.
Which Golang.org/x/crypto versions are affected?
Affected versions include releases prior to 0.0.0-20211202192323-5770296d904e across affected packages: golang.org/x/crypto.
What version fixes CVE-2021-43565?
Upgrading to 0.0.0-20211202192323-5770296d904e (or the latest patched release for your respective branch) resolves the vulnerability.
Is golang.org/x/crypto affected?
Yes, golang.org/x/crypto is affected in releases prior to 0.0.0-20211202192323-5770296d904e. Upgrade your dependency to 0.0.0-20211202192323-5770296d904e or later.
What is the CVSS score of CVE-2021-43565?
CVE-2021-43565 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-43565?
CVE-2021-43565 is classified under General Security Weakness.
How can I check Go dependencies for CVE-2021-43565?
Run the dependency tree command: 'inspect dependencies for golang.org/x/crypto'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gwc9-m7rh-j2ww",
  "modified" : "2023-08-30T13:46:25Z",
  "published" : "2022-09-07T00:01:52Z",
  "aliases" : [ "CVE-2021-43565" ],
  "summary" : "x/crypto/ssh vulnerable to panic via malformed packets",
  "details" : "The x/crypto/ssh package before 0.0.0-20211202192323-5770296d904e of golang.org/x/crypto allows an unauthenticated attacker to panic an SSH server. When using AES-GCM or ChaCha20Poly1305, consuming a malformed packet which contains an empty plaintext causes a panic.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "golang.org/x/crypto"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20211202192323-5770296d904e"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-43565"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/cl/368814"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/issues/49932"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/forum/#!forum/golang-announce"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/golang-announce/c/2AR1sKiM-Qs"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2022-0968"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-09-16T17:40:34Z",
    "nvd_published_at" : "2022-09-06T18:15:00Z"
  }
}