Debian DSA-1992-1 : chrony - several vulnerabilities

medium Nessus Plugin ID 44856

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Synopsis

The remote Debian host is missing a security-related update.

Description

Several vulnerabilities have been discovered in chrony, a pair of programs which are used to maintain the accuracy of the system clock on a computer. This issues are similar to the NTP security flaw CVE-2009-3563. The Common Vulnerabilities and Exposures project identifies the following problems :

- CVE-2010-0292 chronyd replies to all cmdmon packets with NOHOSTACCESS messages even for unauthorized hosts. An attacker can abuse this behaviour to force two chronyd instances to play packet ping-pong by sending such a packet with spoofed source address and port. This results in high CPU and network usage and thus denial of service conditions.

- CVE-2010-0293 The client logging facility of chronyd doesn't limit memory that is used to store client information. An attacker can cause chronyd to allocate large amounts of memory by sending NTP or cmdmon packets with spoofed source addresses resulting in memory exhaustion.

- CVE-2010-0294 chronyd lacks of a rate limit control to the syslog facility when logging received packets from unauthorized hosts. This allows an attacker to cause denial of service conditions via filling up the logs and thus disk space by repeatedly sending invalid cmdmon packets.

Solution

Upgrade the chrony packages.

For the oldstable distribution (etch), this problem has been fixed in version 1.21z-5+etch1.

For the stable distribution (lenny), this problem has been fixed in version 1.23-6+lenny1.

See Also

https://security-tracker.debian.org/tracker/CVE-2009-3563

https://security-tracker.debian.org/tracker/CVE-2010-0292

https://security-tracker.debian.org/tracker/CVE-2010-0293

https://security-tracker.debian.org/tracker/CVE-2010-0294

https://www.debian.org/security/2010/dsa-1992

Plugin Details

Severity: Medium

ID: 44856

File Name: debian_DSA-1992.nasl

Version: 1.13

Type: local

Agent: unix

Published: 2/24/2010

Updated: 1/4/2021

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:chrony, cpe:/o:debian:debian_linux:4.0, cpe:/o:debian:debian_linux:5.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Patch Publication Date: 2/4/2010

Reference Information

CVE: CVE-2010-0292, CVE-2010-0293, CVE-2010-0294

CWE: 20, 399

DSA: 1992