Vulnerability identifier: #VU64997

Vulnerability risk: Low

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2010-4020

CWE-ID: CWE-310

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Kerberos 5
Client/Desktop applications / Software for system administration

Vendor: MIT

Description

The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists due to MIT Kerberos 5 does not reject RC4 key-derivation checksums. A remote user can forge a AD-SIGNEDPATH or AD-KDC-ISSUED signature, and possibly gain privileges, by leveraging the small key space that results from certain one-byte stream-cipher operations.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Kerberos 5: 1.8 - 1.8.3

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External links
http://kb.vmware.com/kb/1035108
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-December/051976.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-December/051999.html
http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00006.html
http://lists.vmware.com/pipermail/security-announce/2011/000133.html
http://osvdb.org/69608
http://secunia.com/advisories/42399
http://support.apple.com/kb/HT4581
http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2010-007.txt
http://www.mandriva.com/security/advisories?name=MDVSA-2010:246
http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html
http://www.redhat.com/support/errata/RHSA-2010-0925.html
http://www.securityfocus.com/archive/1/514953/100/0/threaded
http://www.securityfocus.com/archive/1/517739/100/0/threaded
http://www.securityfocus.com/bid/45117
http://www.securitytracker.com/id?1024803
http://www.ubuntu.com/usn/USN-1030-1
http://www.vmware.com/security/advisories/VMSA-2011-0007.html
http://www.vupen.com/english/advisories/2010/3094
http://www.vupen.com/english/advisories/2010/3095
http://www.vupen.com/english/advisories/2010/3118

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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