WU-FTPD bypass restricted-gid option allows unauthorized access

wuftpd-restrictedgid-gain-access (15423)

High Risk

Description:

Washington University's FTP daemon (WU-FTPD) could allow a remote attacker to gain unauthorized access to the root directory. A remote attacker, who is authenticated, can use chmod to change the permissions on the home directory to deny himself access. When the attacker logs in, WU-FTPD will bypass restrictions on the restricted-gid option and allow the attacker to gain unauthorized access to the root FTP directory.

Platforms Affected:

• Compaq, Tru64 5.1a
• Compaq, Tru64 5.1b
• Debian, Debian Linux 3.0
• HP, HP-UX 11.00
• HP, HP-UX 11.11
• HP, HP-UX 11.22
• HP, HP-UX 11.23
• RedHat, Enterprise Linux 2.1 AW
• RedHat, Enterprise Linux 2.1 ES
• RedHat, Enterprise Linux 2.1 AS
• RedHat, Linux Advanced Workstation 2.1 Itanium
• SGI, ProPack 2.3
• SGI, ProPack 2.4
• Sun, Solaris 9 SPARC
• Sun, Solaris 9 x86
• Turbolinux, Turbolinux Advanced Server 6
• Turbolinux, Turbolinux Server 6.1
• Turbolinux, Turbolinux Workstation 6.0
• Washington University, WU-FTPD 2.4.1
• Washington University, WU-FTPD 2.4.2 Beta18 Academ
• Washington University, WU-FTPD 2.4.2 Beta18 VR10
• Washington University, WU-FTPD 2.4.2 Beta18 VR11
• Washington University, WU-FTPD 2.4.2 Beta18 VR12
• Washington University, WU-FTPD 2.4.2 Beta18 VR13
• Washington University, WU-FTPD 2.4.2 Beta18 VR14
• Washington University, WU-FTPD 2.4.2 Beta18 VR15
• Washington University, WU-FTPD 2.4.2 Beta18 VR4
• Washington University, WU-FTPD 2.4.2 Beta18 VR5
• Washington University, WU-FTPD 2.4.2 Beta18 VR6
• Washington University, WU-FTPD 2.4.2 Beta18 VR7
• Washington University, WU-FTPD 2.4.2 Beta18 VR8
• Washington University, WU-FTPD 2.4.2 Beta18 VR9
• Washington University, WU-FTPD 2.4.2 Beta2 Academ
• Washington University, WU-FTPD 2.4.2 VR16
• Washington University, WU-FTPD 2.4.2 VR17
• Washington University, WU-FTPD 2.5
• Washington University, WU-FTPD 2.6.0
• Washington University, WU-FTPD 2.6.1
• Washington University, WU-FTPD 2.6.2

Remedy:

For Debian GNU/Linux 3.0 (woody):
Upgrade to the latest wu-ftpd package (2.6.2-3woody4 or later), as listed in DSA-457-1. See References.

For Red Hat Linux:
Upgrade to the latest wu-ftpd package, as listed below. Refer to RHSA-2004:096-09 for more information. See References.

Red Hat Enterprise Linux AS (v. 2.1), ES (v. 2.1), and Advanced Workstation for the Itanium Processor (v. 2.6.1-22)

For HP Tru64 UNIX 5.1A and 5.1B:
Apply the appropriate Early Release Patches (ERPs) for your system, as listed in Tru64 Security Bulletin: SSRT4704 and SSRT4705. See References.

For HP-UX 11.00, 11.11, 11.22, and 11.23:
Apply the appropriate patch for this vulnerability, as listed in Hewlett-Packard Security Bulletin HPSBUX01059. See References.

For other distributions:
Contact your vendor for upgrade or patch information.

Consequences:

Gain Access

References:

• CIAC Information Bulletin 0-119, HP Tru64 UNIX WU-FTPD Security Vulnerabilities at http://www.ciac.org/ciac/bulletins/o-119.shtml.
• CIAC Information Bulletin O-095, wu-ftpd 'chmod' and S/Key Vulnerabilities at http://www.ciac.org/ciac/bulletins/o-095.shtml.
• Sun Alert ID: 102356, Security Vulnerability in the Solaris 9 in.ftpd(1M) Server May Allow Unauthorized Directory Access at http://sunsolve.sun.com/search/document.do?assetkey=1-26-102356-1.
• ASA-2006-132: Sun Alert Notifications from Sun Weekly Report dated May 20 2006
• BID-9832: WU-FTPD restricted-gid Unauthorized Access Vulnerability
• CVE-2004-0148: wu-ftpd 2.6.2 and earlier, with the restricted-gid option enabled, allows local users to bypass access restrictions by changing the permissions to prevent access to their home directory, which causes wu-ftpd to use the root directory instead.
• DSA-457: wu-ftpd -- several vulnerabilities
• RHSA-2004-096: wu-ftpd security update
• SA11055: WU-FTPD Directory Access Restriction Bypass Vulnerability
• SA20168: Solaris in.ftpd Directory Access Restriction Bypass Vulnerability

Reported:

Mar 08, 2004

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