CVE-2023-27560: Phpseclib/phpseclib Phpseclib Infinite Loop Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-hm7p-r324-hhf3
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CVSS 7.5
CWE-835
Published
Advisory Summary

CVE-2023-27560 is a HIGH (CVSS 7.5) phpseclib infinite loop vulnerability vulnerability (CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')) affecting Phpseclib/phpseclib libraries in the Packagist ecosystem. The issue involves phpseclib infinite loop vulnerability. Remediation is available by upgrading affected packages to version 3.0.19.

CVE-2023-27560 at a Glance

CVE Identifier CVE-2023-27560
GHSA Identifier GHSA-hm7p-r324-hhf3
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Product Phpseclib/phpseclib
Package Ecosystem Packagist
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-2023-27560

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

phpseclib/phpseclib fixed: 3.0.19 
Upgrade phpseclib/phpseclib to 3.0.19
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 phpseclib/phpseclib

How to Check if You Are Affected

To determine whether your application is affected by CVE-2023-27560, inspect your project dependencies for Phpseclib/phpseclib:

inspect dependencies for phpseclib/phpseclib

Analyze the terminal output to locate any version of Phpseclib/phpseclib in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.0.19), 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 Phpseclib/phpseclib, 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

Math/PrimeField.php in phpseclib has an infinite loop with composite primefields. This vulnerability was introduced in version 3.0.0, and has been patched in 3.0.19. The CVE for this issue originally identified the the vulnerable version as 2.x, however, the vulnerable functionality was not introduced until version 3.

CVE-2023-27560 Affected Phpseclib/phpseclib Versions

1 component(s)
Fixed Versions:
3.0.19
Product / Package Ecosystem Affected Versions Fixed Version
phpseclib/phpseclib
 Packagist
≥ 3.0.0
< 3.0.19
3.0.19

References

NVD — CVE-2023-27560 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-27560
Security Fix Commit FIX COMMIT
https://github.com/phpseclib/phpseclib/commit/6298d1cd55c3ffa44533bd41906caec246b60440
Security Fix Commit FIX COMMIT
https://github.com/phpseclib/phpseclib/commit/6298d1cd55c3ffa44533bd41906caec246b60440#commitcomment-103226722
Phpseclib/phpseclib Source Repository REPOSITORY
https://github.com/phpseclib/phpseclib
Phpseclib/phpseclib Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/phpseclib/phpseclib/CVE-2023-27560.yaml
Phpseclib/phpseclib Release RELEASE
https://github.com/phpseclib/phpseclib/releases/tag/3.0.19

Frequently Asked Questions

What is CVE-2023-27560?
CVE-2023-27560 is a security vulnerability in Phpseclib/phpseclib involving phpseclib Infinite Loop vulnerability under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop').
Which Phpseclib/phpseclib versions are affected?
Affected versions include releases prior to 3.0.19 across affected packages: phpseclib/phpseclib.
What version fixes CVE-2023-27560?
Upgrading to 3.0.19 (or the latest patched release for your respective branch) resolves the vulnerability.
Is phpseclib/phpseclib affected?
Yes, phpseclib/phpseclib is affected in releases prior to 3.0.19. Upgrade your dependency to 3.0.19 or later.
What is the CVSS score of CVE-2023-27560?
CVE-2023-27560 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-2023-27560?
CVE-2023-27560 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 Packagist dependencies for CVE-2023-27560?
Run the dependency tree command: 'inspect dependencies for phpseclib/phpseclib'. 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-hm7p-r324-hhf3",
  "modified" : "2025-03-06T21:36:12Z",
  "published" : "2023-03-03T06:30:17Z",
  "aliases" : [ "CVE-2023-27560" ],
  "summary" : "phpseclib Infinite Loop vulnerability",
  "details" : "Math/PrimeField.php in phpseclib has an infinite loop with composite primefields. This vulnerability was introduced in version 3.0.0, and has been patched in 3.0.19. The CVE for this issue originally identified the the vulnerable version as 2.x, however, the vulnerable functionality was not introduced until version 3.",
  "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" : "Packagist",
      "name" : "phpseclib/phpseclib"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.0.19"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-27560"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/commit/6298d1cd55c3ffa44533bd41906caec246b60440"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/commit/6298d1cd55c3ffa44533bd41906caec246b60440#commitcomment-103226722"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/phpseclib/phpseclib/CVE-2023-27560.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/phpseclib/phpseclib"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/releases/tag/3.0.19"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-03T23:01:05Z",
    "nvd_published_at" : "2023-03-03T06:15:00Z"
  }
}