Denial of service in ntp.org ntp

1) Denial of service

EUVDB-ID: #VU4013

Risk: High

CVSSv4.0: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2013-5211

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to cause DoS conditions on the target system.

The weakness exists due to an error in the monlist feature in ntp_request.c. By sending a specially crafted REQ_MON_GETLIST or REQ_MON_GETLIST_1 request, a remote attacker can consume available CPU resources and cause the server to crash.

Successful exploitation of the vulnerability results in denial of service on the vulnerable system.

Note: the vulnerability was being actively exploited.

Mitigation

Update to version 4.2.7p26.

Vulnerable software versions

ntp: 4.2.7 - 4.2.7p25

CPE2.3

• cpe:2.3:a:ntp_org:ntp:4.2.7:*:*:*:*:*:*:*
• cpe:2.3:a:ntp_org:ntp:4.2.7p25:*:*:*:*:*:*:*

External links

https://aix.software.ibm.com/aix/efixes/security/ntp_advisory.asc
https://bugs.ntp.org/show_bug.cgi?id=1532

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. However, a fully functional exploit for this vulnerability is available.