CVE-2025-21617: Guzzlehttp/oauth subscriber Guzzle OAuth Subscriber Has Insufficient Vulnerability

MODERATE
Advisory Identifier: GHSA-237r-r8m4-4q88
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CWE-338
Published
Advisory Summary

CVE-2025-21617 is a MODERATE guzzle oauth subscriber has insufficient vulnerability (CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)) affecting Guzzlehttp/oauth subscriber libraries in the Packagist ecosystem. The issue involves guzzle oauth subscriber has insufficient nonce entropy. Remediation is available by upgrading affected packages to version 0.8.1.

CVE-2025-21617 at a Glance

CVE Identifier CVE-2025-21617
GHSA Identifier GHSA-237r-r8m4-4q88
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Affected Product Guzzlehttp/oauth subscriber
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2025-21617

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

guzzlehttp/oauth-subscriber fixed: 0.8.1 
Upgrade guzzlehttp/oauth-subscriber to 0.8.1
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 guzzlehttp/oauth-subscriber

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-21617, inspect your project dependencies for Guzzlehttp/oauth subscriber:

inspect dependencies for guzzlehttp/oauth-subscriber

Analyze the terminal output to locate any version of Guzzlehttp/oauth subscriber in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.8.1), 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-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG), where the product uses a pseudo-random number generator (prng) in a security context, but the prng's algorithm is not cryptographically strong. In Guzzlehttp/oauth subscriber, 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

### Impact Nonce generation does not use sufficient entropy nor a cryptographically secure pseudorandom source (https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192). This can leave servers vulnerable to replay attacks when TLS is not used. ### Patches Upgrade to version 0.8.1 or higher. ### Workarounds No. ### References Issue is similar to https://nvd.nist.gov/vuln/detail/CVE-2025-22376.

CVE-2025-21617 Affected Guzzlehttp/oauth subscriber Versions

1 component(s)
Fixed Versions:
0.8.1
Product / Package Ecosystem Affected Versions Fixed Version
guzzlehttp/oauth-subscriber
 Packagist
< 0.8.1
0.8.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/guzzle/oauth-subscriber/security/advisories/GHSA-237r-r8m4-4q88
NVD — CVE-2025-21617 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-21617
Security Fix Commit FIX COMMIT
https://github.com/guzzle/oauth-subscriber/commit/92b619b03bd21396e51c62e6bce83467d2ce8f53
Guzzlehttp/oauth subscriber Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/guzzlehttp/oauth-subscriber/CVE-2025-21617.yaml
Guzzlehttp/oauth subscriber Source Repository REPOSITORY
https://github.com/guzzle/oauth-subscriber
Guzzlehttp/oauth subscriber Source Repository REPOSITORY
https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192
Guzzlehttp/oauth subscriber Release RELEASE
https://github.com/guzzle/oauth-subscriber/releases/tag/0.8.1

Frequently Asked Questions

What is CVE-2025-21617?
CVE-2025-21617 is a security vulnerability in Guzzlehttp/oauth subscriber involving Guzzle OAuth Subscriber has insufficient nonce entropy under CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG).
Which Guzzlehttp/oauth subscriber versions are affected?
Affected versions include releases prior to 0.8.1 across affected packages: guzzlehttp/oauth-subscriber.
What version fixes CVE-2025-21617?
Upgrading to 0.8.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is guzzlehttp/oauth-subscriber affected?
Yes, guzzlehttp/oauth-subscriber is affected in releases prior to 0.8.1. Upgrade your dependency to 0.8.1 or later.
What CWE is associated with CVE-2025-21617?
CVE-2025-21617 is classified under CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) (The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.).
How can I check Packagist dependencies for CVE-2025-21617?
Run the dependency tree command: 'inspect dependencies for guzzlehttp/oauth-subscriber'. 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-237r-r8m4-4q88",
  "modified" : "2026-07-15T21:57:55Z",
  "published" : "2025-01-06T19:23:26Z",
  "aliases" : [ "CVE-2025-21617" ],
  "summary" : "Guzzle OAuth Subscriber has insufficient nonce entropy",
  "details" : "### Impact\n\nNonce generation does not use sufficient entropy nor a cryptographically secure pseudorandom source (https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192). This can leave servers vulnerable to replay attacks when TLS is not used.\n\n### Patches\n\nUpgrade to version 0.8.1 or higher.\n\n### Workarounds\n\nNo.\n\n### References\n\nIssue is similar to https://nvd.nist.gov/vuln/detail/CVE-2025-22376.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "guzzlehttp/oauth-subscriber"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.8.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/guzzle/oauth-subscriber/security/advisories/GHSA-237r-r8m4-4q88"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-21617"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/guzzle/oauth-subscriber/commit/92b619b03bd21396e51c62e6bce83467d2ce8f53"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/guzzlehttp/oauth-subscriber/CVE-2025-21617.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/guzzle/oauth-subscriber"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/guzzle/oauth-subscriber/releases/tag/0.8.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-338" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-01-06T19:23:26Z",
    "nvd_published_at" : "2025-01-06T20:15:39Z"
  }
}