#VU33323 Improper Authentication in FreeRADIUS - CVE-2011-2701

Vulnerability identifier: #VU33323

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2011-2701

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FreeRADIUS
Server applications / Directory software, identity management

Vendor: FreeRADIUS Server Project

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

The ocsp_check function in rlm_eap_tls.c in FreeRADIUS 2.1.11, when OCSP is enabled, does not properly parse replies from OCSP responders, which allows remote attackers to bypass authentication by using the EAP-TLS protocol with a revoked X.509 client certificate.

Mitigation
Install update from vendor's website.

Vulnerable software versions

FreeRADIUS: 2.1.11

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External links
https://secunia.com/advisories/45425
https://securityreason.com/securityalert/8325
https://securitytracker.com/id?1025833
https://www.openwall.com/lists/oss-security/2011/07/15/6
https://www.openwall.com/lists/oss-security/2011/07/18/2
https://www.openwall.com/lists/oss-security/2011/07/20/9
https://www.securityfocus.com/archive/1/518974/100/0/threaded
https://www.securityfocus.com/bid/48880
https://bugzilla.redhat.com/show_bug.cgi?id=724815
https://exchange.xforce.ibmcloud.com/vulnerabilities/68782
https://www.dfn-cert.de/informationen/Sicherheitsbulletins/dsb-2011-01.html

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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.