ls in the fileutils or coreutils packages allows local users to consume a large amount of memory via a large -w value, which can be remotely exploited via applications that use ls, such as wu-ftpd.

Several denial of service conditions have been discovered in wu-ftpd, the popular FTP daemon. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CAN-2005-0256     Adam Zabrocki discovered a denial of service condition     in wu-ftpd that could be exploited by a remote user and     cause the server to slow down by resource exhaustion.

  - CAN-2003-0854

    Georgi Guninski discovered that /bin/ls may be called     from within wu-ftpd in a way that will result in large     memory consumption and hence slow down the server.

A memory starvation denial of service vulnerability in the ls program was discovered by Georgi Guninski. It is possible to allocate a huge amount of memory by specifying certain command-line arguments. It is also possible to exploit this remotely via programs that call ls such as wu-ftpd (although wu-ftpd is no longer shipped with Mandrake Linux).

Likewise, a non-exploitable integer overflow problem was discovered in ls, which can be used to crash ls by specifying certain command-line arguments. This can also be triggered via remotely accessible services such as wu-ftpd.

The provided packages include a patched ls to fix these problems.

Updated fileutils packages that close a potential denial of service vulnerability are now available.

The fileutils package contains several basic system utilities. One of these utilities is the 'ls' program, which is used to list information about files and directories.

Georgi Guninski discovered a memory starvation denial of service vulnerability in the ls program. It is possible to make ls allocate a huge amount of memory by specifying certain command line arguments.
This vulnerability is remotely exploitable through services like wu-ftpd, which pass user arguments to ls. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0854 to this issue.

A non-exploitable integer overflow in ls has been discovered. It is possible to make ls crash by specifying certain command line arguments. This vulnerability is remotely exploitable through services like wu-ftpd, which pass user arguments to ls. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0853 to this issue.

Users are advised to update to these erratum packages, which contain backported security patches that correct these vulnerabilities.

These packages also add support for the O_DIRECT flag, which controls the use of synchronous I/O on file systems such as OCFS.

The version of WU-FTPD on the remote server uses a vulnerable version of /bin/ls. It does not filter arguments to /bin/ls, which could lead to a DoS. It is possible to consume all available memory on the machine  by sending :

ls '-w 1000000 -C'

ID	Name	Product	Family	Severity
18010	Debian DSA-705-1 : wu-ftpd - missing input sanitising	Nessus	Debian Local Security Checks	medium
14088	Mandrake Linux Security Advisory : fileutils/coreutils (MDKSA-2003:106)	Nessus	Mandriva Local Security Checks	medium
12428	RHEL 2.1 : fileutils (RHSA-2003:310)	Nessus	Red Hat Local Security Checks	medium
11912	WU-FTPD fileutils/coreutils ls -w Argument Memory Consumption DoS	Nessus	FTP	high

Detections

Analytics

CVE-2003-0854

medium

Tenable Plugins

medium

medium

medium

high