CVE-2021-33194: Golang.org/x/net Golang.org/x/net/html Infinite Loop Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-83g2-8m93-v3w7
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CVSS 7.5
CWE-835
Published
Advisory Summary

CVE-2021-33194 is a HIGH (CVSS 7.5) golang.org/x/net/html infinite loop vulnerability vulnerability (CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')) affecting Golang.org/x/net libraries in the Go ecosystem. The issue involves golang.org/x/net/html infinite loop vulnerability. Remediation is available by upgrading affected packages to version 0.0.0-20210520170846-37e1c6afe023.

CVE-2021-33194 at a Glance

CVE Identifier CVE-2021-33194
GHSA Identifier GHSA-83g2-8m93-v3w7
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Product Golang.org/x/net
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-2021-33194

To remediate this vulnerability, upgrade all affected Golang.org/x/net 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/net fixed: 0.0.0-20210520170846-37e1c6afe023 
Upgrade golang.org/x/net to 0.0.0-20210520170846-37e1c6afe023
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/net

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-33194, inspect your project dependencies for Golang.org/x/net:

inspect dependencies for golang.org/x/net

Analyze the terminal output to locate any version of Golang.org/x/net in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20210520170846-37e1c6afe023), 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 CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'), where the product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. In Golang.org/x/net, 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

Go through 1.15.12 and 1.16.x through 1.16.4 has a golang.org/x/net/html infinite loop via crafted ParseFragment input.

CVE-2021-33194 Affected Golang.org/x/net Versions

1 component(s)
Fixed Versions:
0.0.0-20210520170846-37e1c6afe023
Product / Package Ecosystem Affected Versions Fixed Version
golang.org/x/net
golang/golang.org/x/net
Go
< 0.0.0-20210520170846-37e1c6afe023
0.0.0-20210520170846-37e1c6afe023

References

NVD — CVE-2021-33194 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33194
Security Fix Commit FIX COMMIT
https://github.com/golang/net/commit/37e1c6afe02340126705deced573a85ab75209d7
go.dev/cl/311090 WEB
https://go.dev/cl/311090
go.dev/issue/46288 WEB
https://go.dev/issue/46288
go.googlesource.com/net/+/37e1c6afe0234... WEB
https://go.googlesource.com/net/+/37e1c6afe02340126705deced573a85ab75209d7
groups.google.com/g/golang-announce/c... WEB
https://groups.google.com/g/golang-announce/c/wPunbCPkWUg
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4CHKSFMHZVOBCZSSVRE3UEYNKARTBMTM
pkg.go.dev/vuln/go-2021-0238 WEB
https://pkg.go.dev/vuln/GO-2021-0238

Frequently Asked Questions

What is CVE-2021-33194?
CVE-2021-33194 is a security vulnerability in Golang.org/x/net involving golang.org/x/net/html Infinite Loop vulnerability under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop').
Which Golang.org/x/net versions are affected?
Affected versions include releases prior to 0.0.0-20210520170846-37e1c6afe023 across affected packages: golang.org/x/net.
What version fixes CVE-2021-33194?
Upgrading to 0.0.0-20210520170846-37e1c6afe023 (or the latest patched release for your respective branch) resolves the vulnerability.
Is golang.org/x/net affected?
Yes, golang.org/x/net is affected in releases prior to 0.0.0-20210520170846-37e1c6afe023. Upgrade your dependency to 0.0.0-20210520170846-37e1c6afe023 or later.
What is the CVSS score of CVE-2021-33194?
CVE-2021-33194 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-2021-33194?
CVE-2021-33194 is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') (The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.).
How can I check Go dependencies for CVE-2021-33194?
Run the dependency tree command: 'inspect dependencies for golang.org/x/net'. 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-83g2-8m93-v3w7",
  "modified" : "2024-05-20T20:30:54Z",
  "published" : "2022-05-24T19:03:21Z",
  "aliases" : [ "CVE-2021-33194" ],
  "summary" : "golang.org/x/net/html Infinite Loop vulnerability",
  "details" : "Go through 1.15.12 and 1.16.x through 1.16.4 has a golang.org/x/net/html infinite loop via crafted ParseFragment input.",
  "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/net"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20210520170846-37e1c6afe023"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-33194"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/golang/net/commit/37e1c6afe02340126705deced573a85ab75209d7"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/cl/311090"
  }, {
    "type" : "WEB",
    "url" : "https://go.dev/issue/46288"
  }, {
    "type" : "WEB",
    "url" : "https://go.googlesource.com/net/+/37e1c6afe02340126705deced573a85ab75209d7"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/golang-announce/c/wPunbCPkWUg"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4CHKSFMHZVOBCZSSVRE3UEYNKARTBMTM"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2021-0238"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-02-08T00:33:11Z",
    "nvd_published_at" : "2021-05-26T15:15:00Z"
  }
}