A certain Red Hat script for sudo 1.7.2 on Red Hat Enterprise Linux (RHEL) 5 allows local users to overwrite arbitrary files via a symlink attack on the /var/tmp/nsswitch.conf.bak temporary file.

The remote VMware ESX / ESXi host is missing a security-related patch.
It is, therefore, affected by multiple vulnerabilities in the bundled version of sudo :

  - An unspecified flaw exists in the sudo package related     to the Network Matching Mechanism that is triggered when     parsing IPv4 netmask hosts. A local attacker can exploit     this to execute arbitrary code. (CVE-2012-2337) 

  - An arbitrary file overwrite vulnerability exists in sudo     due to a race condition occurs in post-uninstall during     the upgrade or removal of sudo packages. A local     attacker can exploit this via a symlink attack against     the /var/tmp/nsswitch.conf.bak file, allowing the     attacker write to a specified file. (CVE-2012-3440)

From Red Hat Security Advisory 2012:1149 :

An updated sudo package that fixes one security issue and several bugs is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The sudo (superuser do) utility allows system administrators to give certain users the ability to run commands as root.

An insecure temporary file use flaw was found in the sudo package's post-uninstall script. A local attacker could possibly use this flaw to overwrite an arbitrary file via a symbolic link attack, or modify the contents of the '/etc/nsswitch.conf' file during the upgrade or removal of the sudo package. (CVE-2012-3440)

This update also fixes the following bugs :

* Previously, sudo escaped non-alphanumeric characters in commands using 'sudo -s' or 'sudo -' at the wrong place and interfered with the authorization process. Some valid commands were not permitted. Now, non-alphanumeric characters escape immediately before the command is executed and no longer interfere with the authorization process.
(BZ#844418)

* Prior to this update, the sudo utility could, under certain circumstances, fail to receive the SIGCHLD signal when it was executed from a process that blocked the SIGCHLD signal. As a consequence, sudo could become suspended and fail to exit. This update modifies the signal process mask so that sudo can exit and sends the correct output. (BZ#844419)

* The sudo update RHSA-2012:0309 introduced a regression that caused the Security-Enhanced Linux (SELinux) context of the '/etc/nsswitch.conf' file to change during the installation or upgrade of the sudo package. This could cause various services confined by SELinux to no longer be permitted to access the file. In reported cases, this issue prevented PostgreSQL and Postfix from starting.
(BZ#842759)

* Updating the sudo package resulted in the 'sudoers' line in '/etc/nsswitch.conf' being removed. This update corrects the bug in the sudo package's post-uninstall script that caused this issue.
(BZ#844420)

* Prior to this update, a race condition bug existed in sudo. When a program was executed with sudo, the program could possibly exit successfully before sudo started waiting for it. In this situation, the program would be left in a zombie state and sudo would wait for it endlessly, expecting it to still be running. (BZ#844978)

All users of sudo are advised to upgrade to this updated package, which contains backported patches to correct these issues.

a. Service Console update for sudo         The service console package sudo is updated to version     1.7.2p1-14.el5_8.3

    The Common Vulnerabilities and Exposures project (cve.mitre.org)     has assigned the name CVE-2012-2337 and CVE-2012-3440 to the issues     addressed in this update.

An insecure temporary file use flaw was found in the sudo package's post-uninstall script. A local attacker could possibly use this flaw to overwrite an arbitrary file via a symbolic link attack, or modify the contents of the '/etc/nsswitch.conf' file during the upgrade or removal of the sudo package. (CVE-2012-3440)

This update also fixes the following bugs :

  - Previously, sudo escaped non-alphanumeric characters in     commands using 'sudo -s' or 'sudo -' at the wrong place     and interfered with the authorization process. Some     valid commands were not permitted. Now, non-alphanumeric     characters escape immediately before the command is     executed and no longer interfere with the authorization     process. (BZ#844418)

  - Prior to this update, the sudo utility could, under     certain circumstances, fail to receive the SIGCHLD     signal when it was executed from a process that blocked     the SIGCHLD signal. As a consequence, sudo could become     suspended and fail to exit. This update modifies the     signal process mask so that sudo can exit and sends the     correct output. (BZ#844419)

  - The sudo update RHSA-2012:0309 introduced a regression     that caused the Security-Enhanced Linux (SELinux)     context of the '/etc/nsswitch.conf' file to change     during the installation or upgrade of the sudo package.
    This could cause various services confined by SELinux to     no longer be permitted to access the file. In reported     cases, this issue prevented PostgreSQL and Postfix from     starting. (BZ#842759)

  - Updating the sudo package resulted in the 'sudoers' line     in '/etc/nsswitch.conf' being removed. This update     corrects the bug in the sudo package's post-uninstall     script that caused this issue. (BZ#844420)

  - Prior to this update, a race condition bug existed in     sudo. When a program was executed with sudo, the program     could possibly exit successfully before sudo started     waiting for it. In this situation, the program would be     left in a zombie state and sudo would wait for it     endlessly, expecting it to still be running. (BZ#844978)

An updated sudo package that fixes one security issue and several bugs is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The sudo (superuser do) utility allows system administrators to give certain users the ability to run commands as root.

An insecure temporary file use flaw was found in the sudo package's post-uninstall script. A local attacker could possibly use this flaw to overwrite an arbitrary file via a symbolic link attack, or modify the contents of the '/etc/nsswitch.conf' file during the upgrade or removal of the sudo package. (CVE-2012-3440)

This update also fixes the following bugs :

* Previously, sudo escaped non-alphanumeric characters in commands using 'sudo -s' or 'sudo -' at the wrong place and interfered with the authorization process. Some valid commands were not permitted. Now, non-alphanumeric characters escape immediately before the command is executed and no longer interfere with the authorization process.
(BZ#844418)

* Prior to this update, the sudo utility could, under certain circumstances, fail to receive the SIGCHLD signal when it was executed from a process that blocked the SIGCHLD signal. As a consequence, sudo could become suspended and fail to exit. This update modifies the signal process mask so that sudo can exit and sends the correct output. (BZ#844419)

* The sudo update RHSA-2012:0309 introduced a regression that caused the Security-Enhanced Linux (SELinux) context of the '/etc/nsswitch.conf' file to change during the installation or upgrade of the sudo package. This could cause various services confined by SELinux to no longer be permitted to access the file. In reported cases, this issue prevented PostgreSQL and Postfix from starting.
(BZ#842759)

* Updating the sudo package resulted in the 'sudoers' line in '/etc/nsswitch.conf' being removed. This update corrects the bug in the sudo package's post-uninstall script that caused this issue.
(BZ#844420)

* Prior to this update, a race condition bug existed in sudo. When a program was executed with sudo, the program could possibly exit successfully before sudo started waiting for it. In this situation, the program would be left in a zombie state and sudo would wait for it endlessly, expecting it to still be running. (BZ#844978)

All users of sudo are advised to upgrade to this updated package, which contains backported patches to correct these issues.

ID	Name	Product	Family	Severity
89665	VMware ESX sudo Package Multiple Vulnerabilities (VMSA-2013-0007) (remote check)	Nessus	Misc.	high
68595	Oracle Linux 5 : sudo (ELSA-2012-1149)	Nessus	Oracle Linux Local Security Checks	medium
66723	VMSA-2013-0007 : VMware ESX third-party update for Service Console package sudo	Nessus	VMware ESX Local Security Checks	high
61456	Scientific Linux Security Update : sudo on SL5.x i386/x86_64 (20120808)	Nessus	Scientific Linux Local Security Checks	medium
61452	RHEL 5 : sudo (RHSA-2012:1149)	Nessus	Red Hat Local Security Checks	medium
61450	CentOS 5 : sudo (CESA-2012:1149)	Nessus	CentOS Local Security Checks	medium

Detections

Analytics

CVE-2012-3440

medium

Tenable Plugins

high

medium

high

medium

medium

medium