CVE-2020-28042
MEDIUMCVSS 5.3/10EPSS 2.33%
Last modified
CVE-2020-28042 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. EPSS estimates a 2.33% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Servicestack | Servicestack | < 5.9.2 |
References
- https://forums.servicestack.net/t/servicestack-v5-9-2-released/8850Release Notes, Vendor Advisory
- https://github.com/ServiceStack/ServiceStack/commit/540d4060e877a03ae95343c1a8560a26768585eePatch, Third Party Advisory
- https://www.shielder.it/advisories/servicestack-jwt-signature-verification-bypass/Exploit, Third Party Advisory
- https://www.shielder.it/blog/2020/11/re-discovering-a-jwt-authentication-bypass-in-servicestack/Exploit, Third Party Advisory
- https://forums.servicestack.net/t/servicestack-v5-9-2-released/8850Release Notes, Vendor Advisory
- https://github.com/ServiceStack/ServiceStack/commit/540d4060e877a03ae95343c1a8560a26768585eePatch, Third Party Advisory
- https://www.shielder.it/advisories/servicestack-jwt-signature-verification-bypass/Exploit, Third Party Advisory
- https://www.shielder.it/blog/2020/11/re-discovering-a-jwt-authentication-bypass-in-servicestack/Exploit, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2020-28042?
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.
How severe is CVE-2020-28042?
CVE-2020-28042 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 2.33% probability of exploitation in the next 30 days.
How do I fix CVE-2020-28042?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
Are you affected by CVE-2020-28042?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST