The nfs_addmntent function in support/nfs/nfs_mntent.c in the mount.nsf tool in nfs-utils before 1.2.4 attempts to append to the /etc/mtab file without first checking whether resource limits would interfere, which allows local users to corrupt this file via a process with a small RLIMIT_FSIZE value, a related issue to CVE-2011-1089.

The remote Oracle Linux 6 host has a package installed that is affected by multiple vulnerabilities as referenced in the ELSA-2011-1534 advisory.

    [1.2.3-15]
    - mout.nfs: Don't roll back to IPv4 whe IPv6 fails (bz 744657)
    - rpcdebug: Added pNFS and FSCache debugging (bz 747400)

    [1.2.3-14]
    - mount.nfs: Backported how upstream handles the SIGXFSZ signal (bz 697981)

    [1.2.3-13]
    - mount.nfs: Reworked the code that deals with RLIMIT_FSIZE (bz 697981)

    [1.2.3-12]
    - Removed the stripping of debugging information from rpcdebug (bz 729001)

    [1.2.3-11]
    - mount.nfs: Fixed problem in mount error verbosity patch (bz 731693)

    [1.2.3-10]
    - mount.nfs: add error verbosity to invalid versions (bz 731693)

    [1.2.3-9]
    - umount.nfs: Got IPV6 unmounts working again (bz 732673)
    - mountd: return multiple hosts exporting the same directory (bz 726112)
    - mount: Better error message for invalid version (bz 723780)

    [1.2.3-8]
    - initscripts: just try to mount rpc_pipefs always (bz 692702)
    - Rely on crypto module autoloading in init scripts
    - svcgssd: Document '-n' for svcgssd (bz 697359)
    - mount.nfs: anticipate RLIMIT_FSIZE (bz 697981)
    - exportfs manpage: Ipv6 update (bz 715078)
    - mountd: Stop segfault in mtab code (bz 723438)
    - exportfs: wilcards in exports can lead to unintended mounts (bz 715391)
    - umount: allow spaces in unmount paths (bz 702273)
    - specfile: reordered how libgssglue is linked in (bz 720479)

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

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

This update fixes the following security issues :

When using wildcards in /etc/exports an attacker could gain unauthorized access to an nfs exported filesystem by creating a DNS record that resolves to the attacker's IP as well as to a trusted IP (CVE-2011-2500).

mount.nfs could corrupt /etc/mtab (CVE-2011-1749).

The remote Oracle Linux 5 host has a package installed that is affected by a vulnerability as referenced in the ELSA-2012-0310 advisory.

    - Mount fails to anticipate RLIMIT_FSIZE (bz 697979,CVE-2011-1749)

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.

The nfs-utils package provides a daemon for the kernel Network File System (NFS) server, and related tools such as the mount.nfs, umount.nfs, and showmount programs.

It was found that the mount.nfs tool did not handle certain errors correctly when updating the mtab (mounted file systems table) file. A local attacker could use this flaw to corrupt the mtab file.
(CVE-2011-1749)

This update also fixes the following bugs :

  - The nfs service failed to start if the NFSv1, NFSv2, and     NFSv4 support was disabled (the MOUNTD_NFS_V1='no',     MOUNTD_NFS_V2='no' MOUNTD_NFS_V3='no' lines in     /etc/sysconfig/nfs were uncommented) because the mountd     daemon failed to handle the settings correctly. With     this update, the underlying code has been modified and     the nfs service starts successfully in the described     scenario.

  - When a user's Kerberos ticket expired, the 'sh rpc.gssd'     messages flooded the /var/log/messages file. With this     update, the excessive logging has been suppressed.

  - The crash simulation (SM_SIMU_CRASH) of the rpc.statd     service had a vulnerability that could be detected by     ISS (Internet Security Scanner). As a result, the     rpc.statd service terminated unexpectedly with the     following error after an ISS scan :

    rpc.statd[xxxx]: recv_rply: can't decode RPC message!     rpc.statd[xxxx]: *** SIMULATING CRASH! ***     rpc.statd[xxxx]: unable to register (statd, 1, udp).

However, the rpc.statd service ignored SM_SIMU_CRASH. This update removes the simulation crash support from the service and the problem no longer occurs.

  - The nfs-utils init scripts returned incorrect status     codes in the following cases: if the rpcgssd and     rpcsvcgssd daemon were not configured, were provided an     unknown argument, their function call failed, if a     program was no longer running and a     /var/lock/subsys/$SERVICE file existed, if starting a     service under an unprivileged user, if a program was no     longer running and its pid file still existed in the     /var/run/ directory. With this update, the correct codes     are returned in these scenarios.

  - The 'nfsstat -m' command did not display NFSv4 mounts.
    With this update, the underlying code has been modified     and the command returns the list of all mounts,     including any NFSv4 mounts, as expected.

  - Previously, the nfs manual pages described the fsc mount     option; however, this option is not supported. This     update removes the option description from the manual     pages.

  - The nfs-utils preinstall scriptlet failed to change the     default group ID for the nfsnobody user to 65534. This     update modifies the preinstall scriptlet and the default     group ID is changed to 65534 after nfs-utils upgrade as     expected.

  - The mount.nfs command with the '-o retry' option did not     try to mount for the time specified in the 'retry=X'     configuration option. This occurred due to incorrect     error handling by the command. With this update, the     underlying code has been fixed and the '-o retry' option     works as expected.

In addition, this update adds the following enhancement :

  - The noresvport option, which allows NFS clients to use     insecure ports (ports above 1023), has been added to the     NFS server configuration options.

All nfs-utils users are advised to upgrade to this updated package, which resolves these issues and adds this enhancement. After installing this update, the nfs service will be restarted automatically.

The nfs-utils packages provide a daemon for the kernel Network File System (NFS) server, and related tools such as the mount.nfs, umount.nfs, and showmount programs.

A flaw was found in the way nfs-utils performed IP based authentication of mount requests. In configurations where a directory was exported to a group of systems using a DNS wildcard or NIS (Network Information Service) netgroup, an attacker could possibly gain access to other directories exported to a specific host or subnet, bypassing intended access restrictions. (CVE-2011-2500)

It was found that the mount.nfs tool did not handle certain errors correctly when updating the mtab (mounted file systems table) file. A local attacker could use this flaw to corrupt the mtab file.
(CVE-2011-1749)

This update also fixes several bugs and adds an enhancement.

Users of nfs-utils are advised to upgrade to these updated packages, which contain backported patches to resolve these issues and add this enhancement. After installing this update, the nfs service will be restarted automatically.

The remote Redhat Enterprise Linux 5 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2012:0310 advisory.

  - nfs-utils: mount.nfs fails to anticipate RLIMIT_FSIZE (CVE-2011-1749)

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

A vulnerability has been discovered and corrected in nfs-utils :

It was found that the mount.nfs tool did not handle certain errors correctly when updating the mtab (mounted file systems table) file. A local attacker could use this flaw to corrupt the mtab file (CVE-2011-1749).

The updated packages have been patched to correct this issue.

Updated nfs-utils packages that fix two security issues, various bugs, and add one enhancement are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having low security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The nfs-utils packages provide a daemon for the kernel Network File System (NFS) server, and related tools such as the mount.nfs, umount.nfs, and showmount programs.

A flaw was found in the way nfs-utils performed IP based authentication of mount requests. In configurations where a directory was exported to a group of systems using a DNS wildcard or NIS (Network Information Service) netgroup, an attacker could possibly gain access to other directories exported to a specific host or subnet, bypassing intended access restrictions. (CVE-2011-2500)

It was found that the mount.nfs tool did not handle certain errors correctly when updating the mtab (mounted file systems table) file. A local attacker could use this flaw to corrupt the mtab file.
(CVE-2011-1749)

This update also fixes several bugs and adds an enhancement.
Documentation for these bug fixes and the enhancement will be available shortly from the Technical Notes document, linked to in the References section.

Users of nfs-utils are advised to upgrade to these updated packages, which contain backported patches to resolve these issues and add this enhancement. After installing this update, the nfs service will be restarted automatically.

ID	Name	Product	Family	Severity
181094	Oracle Linux 6 : nfs-utils (ELSA-2011-1534)	Nessus	Oracle Linux Local Security Checks	critical
75978	openSUSE Security Update : nfs-client (openSUSE-SU-2011:0747-1)	Nessus	SuSE Local Security Checks	high
68481	Oracle Linux 5 : nfs-utils (ELSA-2012-0310)	Nessus	Oracle Linux Local Security Checks	high
61269	Scientific Linux Security Update : nfs-utils on SL5.x i386/x86_64 (20120221)	Nessus	Scientific Linux Local Security Checks	low
61193	Scientific Linux Security Update : nfs-utils on SL6.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
58064	RHEL 5 : nfs-utils (RHSA-2012:0310)	Nessus	Red Hat Local Security Checks	high
57146	Mandriva Linux Security Advisory : nfs-utils (MDVSA-2011:186)	Nessus	Mandriva Local Security Checks	low
57015	RHEL 6 : nfs-utils (RHSA-2011:1534)	Nessus	Red Hat Local Security Checks	high

Detections

Analytics

CVE-2011-1749

high

Tenable Plugins

critical

high

high

low

high

high

low

high