#VU42390 Input validation error in chrony - CVE-2012-4502

Vulnerability identifier: #VU42390

Vulnerability risk: Medium

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

CVE-ID: CVE-2012-4502

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
chrony
Other software / Other software solutions

Vendor: mlichvar

Description

The vulnerability allows remote attackers to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can cause a denial of service (crash) via a crafted (1) REQ_SUBNETS_ACCESSED or (2) REQ_CLIENT_ACCESSES command request to the PKL_CommandLength function or crafted (3) RPY_SUBNETS_ACCESSED, (4) RPY_CLIENT_ACCESSES, (5) RPY_CLIENT_ACCESSES_BY_INDEX, or (6) RPY_MANUAL_LIST command reply to the PKL_ReplyLength function, which triggers an out-of-bounds read or buffer overflow.

Mitigation
Install update from vendor's website.

Vulnerable software versions

chrony: 1.0 - 1.28

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External links
https://git.tuxfamily.org/chrony/chrony.git/?p=chrony/chrony.git;a=commitdiff;h=7712455d9aa33d0db0945effaa07e900b85987b1
https://permalink.gmane.org/gmane.comp.time.chrony.announce/15
https://seclists.org/oss-sec/2013/q3/332
https://www.debian.org/security/2013/dsa-2760
https://bugzilla.redhat.com/show_bug.cgi?id=846392

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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.