JWS and JWT signature validation vulnerability with special characters

CVE-2022-25898 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

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 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

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2022-06-25 07:19:06 UTC
Updated
2023-01-27 05:05:02 UTC
GitHub reviewed
2022-06-25 07:19:06 UTC
NVD published
2022-07-01

EPSS Score

Score Percentile
1.77% 82.50%

CVSS Scores

Base score Version Severity Vector
8.6 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-3fvg-4v2m-98jf ↗
CVE CVE-2022-25898 ↗

CWEs

CWE id Name
CWE-347 Improper Verification of Cryptographic Signature

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm jsrsasign >= 4.8.0, < 10.5.25 10.5.25 —

References

cvelogic Threat Intelligence