CVE-2022-24713: Regex Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-m5pq-gvj9-9vr8
CVSS 7.5
CWE-400 CWE-1333
Published
Advisory Summary

CVE-2022-24713 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Regex libraries in the crates.io ecosystem. The issue involves rust's regex crate vulnerable to regular expression denial of service. Remediation is available by upgrading affected packages to version 1.5.5.

CVE-2022-24713 at a Glance

CVE Identifier CVE-2022-24713
GHSA Identifier GHSA-m5pq-gvj9-9vr8
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Regex
Package Ecosystem crates.io
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-2022-24713

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

regex fixed: 1.5.5
Upgrade regex to 1.5.5
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 regex

How to Check if You Are Affected

To determine whether your application is affected by CVE-2022-24713, inspect your project dependencies for Regex:

inspect dependencies for regex

Analyze the terminal output to locate any version of Regex in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.5.5), 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-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Regex, 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

> This is a cross-post of [the official security advisory][advisory]. The official advisory contains a signed version with our PGP key, as well. [advisory]: https://groups.google.com/g/rustlang-security-announcements/c/NcNNL1Jq7Yw The Rust Security Response WG was notified that the `regex` crate did not properly limit the complexity of the regular expressions (regex) it parses. An attacker could use this security issue to perform a denial of service, by sending a specially crafted regex to a service accepting untrusted regexes. No known vulnerability is present when parsing untrusted input with trusted regexes. This issue has been assigned CVE-2022-24713. The severity of this vulnerability is "high" when the `regex` crate is used to parse untrusted regexes. Other uses of the `regex` crate are not affected by this vulnerability. ## Overview The `regex` crate features built-in mitigations to prevent denial of service attacks caused by untrusted regexes, or untrusted input matched by trusted regexes. Those (tunable) mitigations already provide sane defaults to prevent attacks. This guarantee is documented and it's considered part of the crate's API. Unfortunately a bug was discovered in the mitigations designed to prevent untrusted regexes to take an arbitrary amount of time during parsing, and it's possible to craft regexes that bypass such mitigations. This makes it possible to perform denial of service attacks by sending specially crafted regexes to services accepting user-controlled, untrusted regexes. ## Affected versions All versions of the `regex` crate before or equal to 1.5.4 are affected by this issue. The fix is include starting from `regex` 1.5.5. ## Mitigations We recommend everyone accepting user-controlled regexes to upgrade immediately to the latest version of the `regex` crate. Unfortunately there is no fixed set of problematic regexes, as there are practically infinite regexes that could be crafted to exploit this vulnerability. Because of this, we do not recommend denying known problematic regexes. ## Acknowledgements We want to thank Addison Crump for responsibly disclosing this to us according to the [Rust security policy](https://www.rust-lang.org/policies/security), and for helping review the fix. We also want to thank Andrew Gallant for developing the fix, and Pietro Albini for coordinating the disclosure and writing this advisory.

CVE-2022-24713 Affected Regex Versions

1 component(s)
Fixed Versions:
1.5.5
Product / Package Ecosystem Affected Versions Fixed Version
regex
crates.io
< 1.5.5
1.5.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/rust-lang/regex/security/advisories/GHSA-m5pq-gvj9-9vr8
NVD — CVE-2022-24713 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-24713
Security Fix Commit FIX COMMIT
https://github.com/rust-lang/regex/commit/ae70b41d4f46641dbc45c7a4f87954aea356283e
Regex Source Repository REPOSITORY
https://github.com/rust-lang/regex
Regex Security Information SECURITY
https://groups.google.com/g/rustlang-security-announcements/c/NcNNL1Jq7Yw
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2022/04/msg00003.html
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2022/04/msg00009.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JANLZ3JXWJR7FSHE57K66UIZUIJZI67T
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/O3YB7CURSG64CIPCDPNMGPE4UU24AB6H
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PDOWTHNVGBOP2HN27PUFIGRYNSNDTYRJ
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2022-0013.html
Regex Security Information SECURITY
https://security.gentoo.org/glsa/202208-08
Regex Security Information SECURITY
https://security.gentoo.org/glsa/202208-14
Regex Security Information SECURITY
https://www.debian.org/security/2022/dsa-5113
Regex Security Information SECURITY
https://www.debian.org/security/2022/dsa-5118

Frequently Asked Questions

What is CVE-2022-24713?
CVE-2022-24713 is a security vulnerability in Regex involving Rust's regex crate vulnerable to regular expression denial of service under CWE-400: Uncontrolled Resource Consumption.
Which Regex versions are affected?
Affected versions include releases prior to 1.5.5 across affected packages: regex.
What version fixes CVE-2022-24713?
Upgrading to 1.5.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is regex affected?
Yes, regex is affected in releases prior to 1.5.5. Upgrade your dependency to 1.5.5 or later.
What is the CVSS score of CVE-2022-24713?
CVE-2022-24713 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-2022-24713?
CVE-2022-24713 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check crates.io dependencies for CVE-2022-24713?
Run the dependency tree command: 'inspect dependencies for regex'. 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
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  "id" : "GHSA-m5pq-gvj9-9vr8",
  "modified" : "2022-08-11T20:38:52Z",
  "published" : "2022-03-08T20:00:36Z",
  "aliases" : [ "CVE-2022-24713" ],
  "summary" : "Rust's regex crate vulnerable to regular expression denial of service",
  "details" : "> This is a cross-post of [the official security advisory][advisory]. The official advisory contains a signed version with our PGP key, as well.\n\n[advisory]: https://groups.google.com/g/rustlang-security-announcements/c/NcNNL1Jq7Yw\n\nThe Rust Security Response WG was notified that the `regex` crate did not properly limit the complexity of the regular expressions (regex) it parses. An attacker could use this security issue to perform a denial of service, by sending a specially crafted regex to a service accepting untrusted regexes. No known vulnerability is present when parsing untrusted input with trusted regexes.\n\nThis issue has been assigned CVE-2022-24713. The severity of this vulnerability is \"high\" when the `regex` crate is used to parse untrusted regexes. Other uses of the `regex` crate are not affected by this vulnerability.\n\n## Overview\n\nThe `regex` crate features built-in mitigations to prevent denial of service attacks caused by untrusted regexes, or untrusted input matched by trusted regexes. Those (tunable) mitigations already provide sane defaults to prevent attacks. This guarantee is documented and it's considered part of the crate's API.\n\nUnfortunately a bug was discovered in the mitigations designed to prevent untrusted regexes to take an arbitrary amount of time during parsing, and it's possible to craft regexes that bypass such mitigations. This makes it possible to perform denial of service attacks by sending specially crafted regexes to services accepting user-controlled, untrusted regexes.\n\n## Affected versions\n\nAll versions of the `regex` crate before or equal to 1.5.4 are affected by this issue. The fix is include starting from  `regex` 1.5.5.\n\n## Mitigations\n\nWe recommend everyone accepting user-controlled regexes to upgrade immediately to the latest version of the `regex` crate.\n\nUnfortunately there is no fixed set of problematic regexes, as there are practically infinite regexes that could be crafted to exploit this vulnerability. Because of this, we do not recommend denying known problematic regexes.\n\n## Acknowledgements\n\nWe want to thank Addison Crump for responsibly disclosing this to us according to the [Rust security policy](https://www.rust-lang.org/policies/security), and for helping review the fix.\n\nWe also want to thank Andrew Gallant for developing the fix, and Pietro Albini for coordinating the disclosure and writing this advisory.",
  "severity" : [ {
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    "url" : "https://lists.debian.org/debian-lts-announce/2022/04/msg00009.html"
  }, {
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    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JANLZ3JXWJR7FSHE57K66UIZUIJZI67T"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/O3YB7CURSG64CIPCDPNMGPE4UU24AB6H"
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  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333", "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-03-08T20:00:36Z",
    "nvd_published_at" : "2022-03-08T19:15:00Z"
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}