Improper certificate validation in Stunnel



Published: 2021-02-22
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-20230
CWE-ID CWE-295
Exploitation vector Network
Public exploit N/A
Vulnerable software
Subscribe 		Stunnel
Client/Desktop applications / Encryption software

Vendor Stunnel.org

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Improper Certificate Validation

EUVDB-ID: #VU50843

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20230

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to improper client certificate validation, when redirect and verifyChain options are used. A remote attacker can bypass implemented security restrictions with a any valid certificated and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Stunnel: 5.00 - 5.56

External links

http://www.redhat.com/security/data/cve/CVE-2021-20230.html
http://bugzilla.redhat.com/show_bug.cgi?id=1925226


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



###SIDEBAR###