A certain Red Hat modification to the ChrootDirectory feature in OpenSSH 4.8, as used in sshd in OpenSSH 4.3 in Red Hat Enterprise Linux (RHEL) 5.4 and Fedora 11, allows local users to gain privileges via hard links to setuid programs that use configuration files within the chroot directory, related to requirements for directory ownership.

The remote VMware ESX host is missing a security-related patch. It is, therefore, affected by multiple vulnerabilities, including remote code execution vulnerabilities, in several third-party components and libraries :

  - bind
  - expat
  - glib2
  - Kernel
  - newt
  - nfs-utils
  - NTP
  - OpenSSH
  - OpenSSL

A certain Red Hat modification to the ChrootDirectory feature in OpenSSH 4.8, as used in sshd in OpenSSH 4.3 in Red Hat Enterprise Linux (RHEL) 5.4 and Fedora 11, allows local users to gain privileges via hard links to setuid programs that use configuration files within the chroot directory, related to requirements for directory ownership.
(CVE-2009-2904)

The remote Oracle Linux 5 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2009-1470 advisory.

    [4.3p2-36.2]
    - minimize chroot patch to be compatible with upstream (#522141)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

A Red Hat specific patch used in the openssh packages as shipped in Red Hat Enterprise Linux 5.4 (RHSA-2009:1287) loosened certain ownership requirements for directories used as arguments for the ChrootDirectory configuration options. A malicious user that also has or previously had non-chroot shell access to a system could possibly use this flaw to escalate their privileges and run commands as any system user. (CVE-2009-2904)

After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

According to its banner, the version of OpenSSH running on the remote host may have a privilege escalation vulnerability.  OpenSSH on Red Hat Enterprise Linux 5, Fedora 11, and possibly other platforms use an insecure implementation of the 'ChrootDirectory' configuration setting, which could allow privilege escalation.  Upstream OpenSSH is not affected. 

The fix for this issue does not change the version in the OpenSSH banner, so this may be a false positive.

Rollback chroot patch

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

a. vMA and Service Console update for newt to 0.52.2-12.el5_4.1

   Newt is a programming library for color text mode, widget based    user interfaces. Newt can be used to add stacked windows, entry    widgets, checkboxes, radio buttons, labels, plain text fields,    scrollbars, etc., to text mode user interfaces.

   A heap-based buffer overflow flaw was found in the way newt    processes content that is to be displayed in a text dialog box.
   A local attacker could issue a specially crafted text dialog box    display request (direct or via a custom application), leading to a    denial of service (application crash) or, potentially, arbitrary    code execution with the privileges of the user running the    application using the newt library.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2009-2905 to this issue.

b. vMA and Service Console update for vMA package nfs-utils to    1.0.9-42.el5

   The nfs-utils package provides a daemon for the kernel NFS server    and related tools.

   It was discovered that nfs-utils did not use tcp_wrappers    correctly.  Certain hosts access rules defined in '/etc/hosts.allow'    and '/etc/hosts.deny' may not have been honored, possibly allowing    remote attackers to bypass intended access restrictions.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2008-4552 to this issue.

c. vMA and Service Console package glib2 updated to 2.12.3-4.el5_3.1

   GLib is the low-level core library that forms the basis for    projects such as GTK+ and GNOME. It provides data structure    handling for C, portability wrappers, and interfaces for such    runtime functionality as an event loop, threads, dynamic loading,    and an object system.

   Multiple integer overflows in glib/gbase64.c in GLib before 2.20    allow context-dependent attackers to execute arbitrary code via a    long string that is converted either from or to a base64    representation.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2008-4316 to this issue.

d. vMA and Service Console update for openssl to 0.9.8e-12.el5

   SSL is a toolkit implementing SSL v2/v3 and TLS protocols with full-    strength cryptography world-wide.

   Multiple denial of service flaws were discovered in OpenSSL's DTLS    implementation. A remote attacker could use these flaws to cause a    DTLS server to use excessive amounts of memory, or crash on an    invalid memory access or NULL pointer dereference.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the names CVE-2009-1377, CVE-2009-1378,    CVE-2009-1379, CVE-2009-1386, CVE-2009-1387 to these issues.

   An input validation flaw was found in the handling of the BMPString    and UniversalString ASN1 string types in OpenSSL's    ASN1_STRING_print_ex() function. An attacker could use this flaw to    create a specially crafted X.509 certificate that could cause    applications using the affected function to crash when printing    certificate contents.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2009-0590 to this issue.

e. vMA and Service Console package bind updated to 9.3.6-4.P1.el5_4.1

   It was discovered that BIND was incorrectly caching responses    without performing proper DNSSEC validation, when those responses    were received during the resolution of a recursive client query    that requested DNSSEC records but indicated that checking should be    disabled. A remote attacker could use this flaw to bypass the DNSSEC    validation check and perform a cache poisoning attack if the target    BIND server was receiving such client queries.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2009-4022 to this issue.

f. vMA and Service Console package expat updated to 1.95.8-8.3.el5_4.2.

   Two buffer over-read flaws were found in the way Expat handled    malformed UTF-8 sequences when processing XML files. A specially-    crafted XML file could cause applications using Expat to fail while    parsing the file.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the names CVE-2009-3560 and CVE-2009-3720 to these    issues.

g. vMA and Service Console package openssh update to 4.3p2-36.el5_4.2

   A Red Hat specific patch used in the openssh packages as shipped in    Red Hat Enterprise Linux 5.4 (RHSA-2009:1287) loosened certain    ownership requirements for directories used as arguments for the    ChrootDirectory configuration options. A malicious user that also    has or previously had non-chroot shell access to a system could    possibly use this flaw to escalate their privileges and run    commands as any system user.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2009-2904 to this issue.

h. vMA and Service Console package ntp updated to    ntp-4.2.2p1-9.el5_4.1.i386.rpm

   A flaw was discovered in the way ntpd handled certain malformed NTP    packets. ntpd logged information about all such packets and replied    with an NTP packet that was treated as malformed when received by    another ntpd. A remote attacker could use this flaw to create an NTP    packet reply loop between two ntpd servers through a malformed packet    with a spoofed source IP address and port, causing ntpd on those    servers to use excessive amounts of CPU time and fill disk space with    log messages.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the name CVE-2009-3563 to this issue.   

i. vMA update for package kernel to 2.6.18-164.9.1.el5

   Updated vMA package kernel addresses the security issues listed    below.

   The Common Vulnerabilities and Exposures project (cve.mitre.org)    has assigned the name CVE-2009-2849 to the security issue fixed in    kernel 2.6.18-128.2.1

   The Common Vulnerabilities and Exposures project (cve.mitre.org)    has assigned the names CVE-2009-2695, CVE-2009-2908, CVE-2009-3228,    CVE-2009-3286, CVE-2009-3547, CVE-2009-3613 to the security issues    fixed in kernel 2.6.18-128.6.1

   The Common Vulnerabilities and Exposures project (cve.mitre.org)    has assigned the names CVE-2009-3612, CVE-2009-3620, CVE-2009-3621,    CVE-2009-3726 to the security issues fixed in kernel    2.6.18-128.9.1

j. vMA 4.0 updates for the packages kpartx, libvolume-id,    device-mapper-multipath, fipscheck, dbus, dbus-libs, and ed

   kpartx updated to 0.4.7-23.el5_3.4, libvolume-id updated to    095-14.20.el5 device-mapper-multipath package updated to    0.4.7-23.el5_3.4, fipscheck updated to 1.0.3-1.el5, dbus    updated to 1.1.2-12.el5, dbus-libs updated to 1.1.2-12.el5,    and ed package updated to 0.2-39.el5_2.

   The Common Vulnerabilities and Exposures Project (cve.mitre.org)    has assigned the names CVE-2008-3916, CVE-2009-1189 and    CVE-2009-0115 to these issues.

Updated openssh packages that fix a security issue are now available for Red Hat Enterprise Linux 5.

This update has been rated as having moderate security impact by the Red Hat Security Response Team.

OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages include the core files necessary for both the OpenSSH client and server.

A Red Hat specific patch used in the openssh packages as shipped in Red Hat Enterprise Linux 5.4 (RHSA-2009:1287) loosened certain ownership requirements for directories used as arguments for the ChrootDirectory configuration options. A malicious user that also has or previously had non-chroot shell access to a system could possibly use this flaw to escalate their privileges and run commands as any system user. (CVE-2009-2904)

All OpenSSH users are advised to upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2009:1470 advisory.

    OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These     packages include the core files necessary for both the OpenSSH client and     server.

    A Red Hat specific patch used in the openssh packages as shipped in Red     Hat Enterprise Linux 5.4 (RHSA-2009:1287) loosened certain ownership     requirements for directories used as arguments for the ChrootDirectory     configuration options. A malicious user that also has or previously had     non-chroot shell access to a system could possibly use this flaw to     escalate their privileges and run commands as any system user.
    (CVE-2009-2904)

    All OpenSSH users are advised to upgrade to these updated packages, which     contain a backported patch to resolve this issue. After installing this     update, the OpenSSH server daemon (sshd) will be restarted automatically.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
89737	VMware ESX Third-Party Libraries Multiple Vulnerabilities (VMSA-2010-0004) (remote check)	Nessus	VMware ESX Local Security Checks	high
78162	F5 Networks BIG-IP : OpenSSH vulnerability (SOL15156)	Nessus	F5 Networks Local Security Checks	medium
67933	Oracle Linux 5 : openssh (ELSA-2009-1470)	Nessus	Oracle Linux Local Security Checks	high
60671	Scientific Linux Security Update : openssh on SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
17706	Red Hat Enterprise Linux OpenSSH ChrootDirectory Local Privilege Escalation	Nessus	Misc.	medium
47388	Fedora 11 : openssh-5.2p1-6.fc11 (2010-5429)	Nessus	Fedora Local Security Checks	medium
44993	VMSA-2010-0004 : ESX Service Console and vMA third-party updates	Nessus	VMware ESX Local Security Checks	high
43797	CentOS 5 : openssh (CESA-2009:1470)	Nessus	CentOS Local Security Checks	medium
41951	RHEL 5 : openssh (RHSA-2009:1470)	Nessus	Red Hat Local Security Checks	critical

Detections

Analytics

CVE-2009-2904

critical

Tenable Plugins

high

medium

high

medium

medium

medium

high

medium

critical