Vulnerability · Published Nov 1, 2020 · Assigned by mitre
CVE-2020-28042
Medium 5.3
In plain English
A medium-severity security flaw in the servicestack package (NuGet). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.3% (higher than 84% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)5.3Medium
Exploit odds (30 days)2.3%top 16.3% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC
Official description
ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has a custom ValidateToken function that establishes a valid minimum length for a signature.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| NuGet | servicestack | 5.9.2 | GHSA-v5rv-hpxg-8x49 |
Affected products (as reported)
References
- https://forums.servicestack.net/t/servicestack-v5-9-2-released/8850 x_refsource_MISC
- https://github.com/ServiceStack/ServiceStack/commit/540d4060e877a03ae95343c1a8560a26768585ee x_refsource_MISC
- https://www.shielder.it/blog/2020/11/re-discovering-a-jwt-authentication-bypass-in-servicestack/ x_refsource_MISC
- https://www.shielder.it/advisories/servicestack-jwt-signature-verification-bypass/ x_refsource_MISC