yii2-authclient vulnerable to possible timing attack on string comparison in OAuth1, OAuth2 and OpenID Connect implementation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2023-50708: 0.72% estimated exploitation activity in the next 30 days; percentile 53.83 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact What kind of vulnerability is it? Who is impacted? Original Report: The Oauth1/2 "state" and OpenID Connect "nonce" is vulnerable for a "timing attack" since it's compared via regular string comparison (instead of Yii::$app-getSecurity()-compareString()). Affected Code: 1. OAuth 1 "state" https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OAuth1.php#L158 3. OAuth 2 "state" https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OAuth2.php#L121 4. OpenID Connect "nonce" https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OpenIdConnect.php#L420 Patches Has the problem been patched? What versions should users upgrade to? TBD: Replace strcmp with Yii::$app-getSecurity()-compareString()). Workarounds Is there a way for users to fix or remediate the vulnerability without upgrading? not as far as I see. References Are there any links users can visit to find out more?

Published by the source

18 Dec 2023, 20:01 UTC

Last modified by the source

22 Dec 2023, 22:23 UTC

Source last checked

26 Oct 2026, 14:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-w8vh-p74j-x9xp

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# Patch Next advisory brief: CVE-2023-50708

Advisory: yii2-authclient vulnerable to possible timing attack on string comparison in OAuth1, OAuth2 and OpenID Connect implementation
IDs: CVE-2023-50708, GHSA-w8vh-p74j-x9xp
Record: https://patchnext.com/advisories/cve-2023-50708 (revision 1, source checked 26 Oct 2026, 14:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: yiisoft/yii2-authclient 2.2.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist yiisoft/yii2-authclient: affected <= 2.2.14; fixed in 2.2.15

## Suggested inspection (read-only)
- Packagist yiisoft/yii2-authclient: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on yiisoft/yii2-authclient.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-w8vh-p74j-x9xp (GitHub-reviewed advisory GHSA-w8vh-p74j-x9xp lists affected ranges: Packagist yiisoft/yii2-authclient >=0 <=2.2.14)

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