Buffer overflow in the QFILEPATHINFO request handler in Samba 3.0.x through 3.0.7 may allow remote attackers to execute arbitrary code via a TRANSACT2_QFILEPATHINFO request with a small "maximum data bytes" value.

CAN-2004-0883, CAN-2004-0949 :

During an audit of the smb file system implementation within Linux, several vulnerabilities were discovered ranging from out of bounds read accesses to kernel level buffer overflows.

To exploit any of these vulnerabilities, an attacker needs control over the answers of the connected Samba server. This could be achieved by man-in-the-middle attacks or by taking over the Samba server with e. g. the recently disclosed vulnerability in Samba 3.x (see CAN-2004-0882).

While any of these vulnerabilities can be easily used as remote denial of service exploits against Linux systems, it is unclear if it is possible for a skilled local or remote attacker to use any of the possible buffer overflows for arbitrary code execution in kernel space. So these bugs may theoretically lead to privilege escalation and total compromise of the whole system.

http://isec.pl/vulnerabilities/isec-0017-binfmt_elf.txt :

Several flaws have been found in the Linux ELF binary loader's handling of setuid binaries. Nowadays ELF is the standard format for Linux executables and libraries. setuid binaries are programs that have the 'setuid' file permission bit set; they allow to execute a program under a user id different from the calling user and are mostly used to allow executing a program with root privileges to normal users.

The vulnerabilities that were fixed in these updated kernel packages could lead Denial of Service attacks. They also might lead to execution of arbitrary code and privilege escalation on some platforms if an attacker is able to run setuid programs under some special system conditions (like very little remaining memory).

Another flaw could allow an attacker to read supposedly unreadable, but executable suid binaries. The attacker can then use this to seek faults within the executable.

http://marc.theaimsgroup.com/?l=linux-kernel&m=109776571411003&w=2 :

Bernard Gagnon discovered a memory leak in the mmap raw packet socket implementation. When a client application (in ELF format) core dumps, a region of memory stays allocated as a ring buffer. This could be exploited by a malicious user who repeatedly crashes certain types of applications until the memory is exhausted, thus causing a Denial of Service.

Reverted 486 emulation patch :

Ubuntu kernels for the i386 platforms are compiled using the i486 instruction set for performance reasons. Former Ubuntu kernels contained code which emulated the missing instructions on real 386 processors. However, several actual and potential security flaws have been discovered in the code, and it was found to be unsupportable. It might be possible to exploit these vulnerabilities also on i486 and higher processors.

Therefore support for real i386 processors has ceased. This updated kernel will only run on i486 and newer processors.

Other architectures supported by Ubuntu (amd64, powerpc) are not affected.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

During an audit of the Samba 3.x code base Stefan Esser discovered a Unicode file name buffer overflow within the handling of TRANSACT2_QFILEPATHINFO replies. A malicious samba user with write access to a share could exploit this by creating specially crafted path names (files with very long names containing Unicode characters) that would overflow an internal buffer and could lead to remote execution of arbitrary code with the privileges of the samba server.

Since the samba server usually (by default) runs as root, this flaw can lead to privilege escalation and unbounded system compromise.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Caused by improper bounds checking of certain trans2 requests, there is a possible buffer overrun in smbd. The attacker needs to be able to create files with very specific Unicode filenames on the share to take advantage of this issue.

Steffan Esser discovered that invalid bounds checking in reply to certain trans2 requests could result in a buffer overrun in smbd. This can only be exploited by a malicious user able to create files with very specific Unicode filenames on a samba share.

The updated packages have been patched to prevent this problem.

Updated samba packages that fix various security vulnerabilities are now available.

Samba provides file and printer sharing services to SMB/CIFS clients.

During a code audit, Stefan Esser discovered a buffer overflow in Samba versions prior to 3.0.8 when handling unicode filenames. An authenticated remote user could exploit this bug which may lead to arbitrary code execution on the server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0882 to this issue. Red Hat believes that the Exec-Shield technology (enabled by default since Update 3) will block attempts to remotely exploit this vulnerability on x86 architectures.

Additionally, a bug was found in the input validation routines in versions of Samba prior to 3.0.8 that caused the smbd process to consume abnormal amounts of system memory. An authenticated remote user could exploit this bug to cause a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0930 to this issue.

Users of Samba should upgrade to these updated packages, which contain backported security patches, and are not vulnerable to these issues.

The remote host is missing the patch for the advisory SUSE-SA:2004:040 (samba).


There is a problem in the Samba file sharing service daemon, which allows a remote user to have the service consume lots of computing power and potentially crash the service by querying special wildcarded filenames.

This attack can be successful if the Samba daemon is running and a remote user has access to a share (even read only).

The Samba team has issued the new Samba version 3.0.8 to fix this problem, this update backports the relevant patch.

This issue has been assigned the Mitre CVE ID CVE-2004-0930.


Stefan Esser found a problem in the Unicode string handling in the Samba file handling which could lead to a remote heap buffer overflow and might allow remote attackers to inject code in the smbd process.

This issue has been assigned the Mitre CVE ID CVE-2004-0882.


We provide updated packages for both these problems.

The Samba version 2 packages are not affected by this problem.

The remote Samba server, according to its version number, is affected by a remote denial of service vulnerability as well as a buffer overflow. 

The Wild Card DoS vulnerability may allow an attacker to make the remote server consume excessive CPU cycles. 

The QFILEPATHINFO Remote buffer overflow vulnerability may allow an attacker to execute code on the server. 

An attacker needs a valid account or enough credentials to exploit those flaws.

The remote host is affected by the vulnerability described in GLSA-200411-21 (Samba: Multiple vulnerabilities)

    Samba fails to do proper bounds checking when handling     TRANSACT2_QFILEPATHINFO replies. Additionally an input validation flaw     exists in ms_fnmatch.c when matching filenames that contain wildcards.
  Impact :

    An attacker may be able to execute arbitrary code with the permissions     of the user running Samba. A remote attacker may also be able to cause     an abnormal consumption of CPU resources, resulting in slower     performance of the server or even a Denial of Service.
  Workaround :

    There is no known workaround at this time.

The remote Samba server, according to its version number, may be vulnerable to a remote Denial Of Service vulnerability and a remote buffer overflow.
 The Wild Card DoS vulnerability may allow an attacker to make the remote server consume excessive CPU cycles.
The QFILEPATHINFO remote buffer overflow vulnerability may allow an attacker to execute code on the server.
 An attacker needs credentials to exploit those flaws. 

ID	Name	Product	Family	Severity
20646	Ubuntu 4.10 : linux-source-2.6.8.1 vulnerabilities (USN-30-1)	Nessus	Ubuntu Local Security Checks	critical
20644	Ubuntu 4.10 : samba vulnerability (USN-29-1)	Nessus	Ubuntu Local Security Checks	critical
19169	FreeBSD : smbd -- buffer-overrun vulnerability (f3d3f621-38d8-11d9-8fff-000c6e8f12ef)	Nessus	FreeBSD Local Security Checks	critical
15769	Mandrake Linux Security Advisory : samba (MDKSA-2004:136)	Nessus	Mandriva Local Security Checks	critical
15741	RHEL 2.1 / 3 : samba (RHSA-2004:632)	Nessus	Red Hat Local Security Checks	critical
15726	SUSE-SA:2004:040: samba	Nessus	SuSE Local Security Checks	critical
15705	Samba Multiple Remote Vulnerabilities	Nessus	Misc.	high
15696	GLSA-200411-21 : Samba: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	critical
2397	Samba < 3.0.8 Remote Wild Card DoS and QFILEPATHINFO Remote Overflow	Nessus Network Monitor	Samba	high

Detections

Analytics

CVE-2004-0882

critical

Tenable Plugins

critical

critical

critical

critical

critical

critical

high

critical

high