CVE-2022-25898
JWS and JWT signature validation vulnerability with special characters
Description
### Impact Jsrsasign supports JWS(JSON Web Signatures) and JWT(JSON Web Token) validation. However JWS or JWT signature with non Base64URL encoding special characters or number escaped characters may be validated as valid by mistake. For example, even if a string of non Base64URL encoding characters such as `!@$%` or `\11` is inserted into a valid JWS or JWT signature value string, it will still be a valid JWS or JWT signature by mistake. When jsrsasign's JWS or JWT validation is used in OpenID connect or OAuth2, this vulnerability will affect to authentication or authorization. By our internal assessment, CVSS 3.1 score will be 8.6. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N ### Patches Users validate JWS or JWT signatures should upgrade to 10.5.25. ### Workarounds Validate JWS or JWT signature if it has Base64URL and dot safe string before executing JWS.verify() or JWS.verifyJWT() method. ### ACKNOWLEDGEMENT Thanks to Adi Malyanker and Or David for this vulnerability report. Also thanks for [Snyk security team](https://snyk.io/) for this coordination. ### References https://github.com/kjur/jsrsasign/releases/tag/10.5.25 https://github.com/kjur/jsrsasign/security/advisories/GHSA-3fvg-4v2m-98jf kjur's advisories https://github.com/advisories/GHSA-3fvg-4v2m-98jf github advisories https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-25898 https://kjur.github.io/jsrsasign/api/symbols/KJUR.jws.JWS.html#.verifyJWT https://kjur.github.io/jsrsasign/api/symbols/KJUR.jws.JWS.html#.verify https://kjur.github.io/jsrsasign/api/symbols/global__.html#.isBase64URLDot https://github.com/kjur/jsrsasign/wiki/Tutorial-for-JWS-verification https://github.com/kjur/jsrsasign/wiki/Tutorial-for-JWT-verification https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-2869122
How to fix CVE-2022-25898
To remediate CVE-2022-25898, upgrade the affected package to a fixed version below.
- —upgrade to 10.5.25 or later
Is CVE-2022-25898 being exploited?
Low — EPSS is 1.8%, meaning exploitation activity has not been observed at scale.