Debian DSA-2305-1 : vsftpd - denial of service

high Nessus Plugin ID 56231

Synopsis

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

Description

Two security issue have been discovered that affect vsftpd, a lightweight, efficient FTP server written for security.

- CVE-2011-2189 It was discovered that Linux kernels < 2.6.35 are considerably slower in releasing than in the creation of network namespaces. As a result of this and because vsftpd is using this feature as a security enhancement to provide network isolation for connections, it is possible to cause denial of service conditions due to excessive memory allocations by the kernel. This is technically no vsftpd flaw, but a kernel issue. However, this feature has legitimate use cases and backporting the specific kernel patch is too intrusive.
Additionally, a local attacker requires the CAP_SYS_ADMIN capability to abuse this functionality.
Therefore, as a fix, a kernel version check has been added to vsftpd in order to disable this feature for kernels < 2.6.35.

- CVE-2011-0762 Maksymilian Arciemowicz discovered that vsftpd is incorrectly handling certain glob expressions in STAT commands. This allows a remote authenticated attacker to conduct denial of service attacks (excessive CPU and process slot exhaustion) via crafted STAT commands.

Solution

Upgrade the vsftpd packages.

For the oldstable distribution (lenny), this problem has been fixed in version 2.0.7-1+lenny1.

For the stable distribution (squeeze), this problem has been fixed in version 2.3.2-3+squeeze2. Please note that CVE-2011-2189 does not affect the lenny version.

See Also

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=622741

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=629373

https://security-tracker.debian.org/tracker/CVE-2011-2189

https://security-tracker.debian.org/tracker/CVE-2011-0762

https://packages.debian.org/source/squeeze/vsftpd

https://www.debian.org/security/2011/dsa-2305

Plugin Details

Severity: High

ID: 56231

File Name: debian_DSA-2305.nasl

Version: 1.12

Type: local

Agent: unix

Published: 9/20/2011

Updated: 1/11/2021

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:vsftpd, cpe:/o:debian:debian_linux:5.0, cpe:/o:debian:debian_linux:6.0

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/19/2011

Reference Information

CVE: CVE-2011-0762, CVE-2011-2189

BID: 46617

DSA: 2305