neon before 0.28.6, when expat is used, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.

The remote Redhat Enterprise Linux 4 host has one or more packages installed that are affected by a vulnerability that has been acknowledged by the vendor but will not be patched.

  - neon: billion laughs DoS attack (CVE-2009-2473)

Note that Nessus has not tested for this issue but has instead relied on the package manager's report that the package is installed.

From Red Hat Security Advisory 2013:0131 :

Updated gnome-vfs2 packages that fix one security issue and several bugs are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low 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 gnome-vfs2 packages provide the GNOME Virtual File System, which is the foundation of the Nautilus file manager. neon is an HTTP and WebDAV client library embedded in the gnome-vfs2 packages.

A denial of service flaw was found in the neon Extensible Markup Language (XML) parser. Visiting a malicious DAV server with an application using gnome-vfs2 (such as Nautilus) could possibly cause the application to consume an excessive amount of CPU and memory.
(CVE-2009-2473)

This update also fixes the following bugs :

* When extracted from the Uniform Resource Identifier (URI), gnome-vfs2 returned escaped file paths. If a path, as stored in the URI, contained non-ASCII characters or ASCII characters which are parsed as something other than a file path (for example, spaces), the escaped path was inaccurate. Consequently, files with the described type of URI could not be processed. With this update, gnome-vfs2 properly unescapes paths that are required for a system call. As a result, these paths are parsed properly. (BZ#580855)

* In certain cases, the trash info file was populated by foreign entries, pointing to live data. Emptying the trash caused an accidental deletion of valuable data. With this update, a workaround has been applied in order to prevent the deletion. As a result, the accidental data loss is prevented, however further information is still gathered to fully fix this problem. (BZ#586015)

* Due to a wrong test checking for a destination file system, the Nautilus file manager failed to delete a symbolic link to a folder which was residing in another file system. With this update, a special test has been added. As a result, a symbolic link pointing to another file system can be trashed or deleted properly. (BZ#621394)

* Prior to this update, when directories without a read permission were marked for copy, the Nautilus file manager skipped these unreadable directories without notification. With this update, Nautilus displays an error message and properly informs the user about the aforementioned problem. (BZ#772307)

* Previously, gnome-vfs2 used the stat() function calls for every file on the MultiVersion File System (MVFS), used for example by IBM Rational ClearCase. This behavior significantly slowed down file operations. With this update, the unnecessary stat() operations have been limited. As a result, gnome-vfs2 user interfaces, such as Nautilus, are more responsive. (BZ#822817)

All gnome-vfs2 users are advised to upgrade to these updated packages, which contain backported patches to correct these issues.

The remote Oracle Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2009-1452 advisory.

    [0.25.5-10.el5_4.1]
    - add security fixes for CVE-2009-2473 CVE-2009-2474 (#521788)

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.

A denial of service flaw was found in the neon Extensible Markup Language (XML) parser. Visiting a malicious DAV server with an application using gnome-vfs2 (such as Nautilus) could possibly cause the application to consume an excessive amount of CPU and memory.
(CVE-2009-2473)

This update also fixes the following bugs :

  - When extracted from the Uniform Resource Identifier     (URI), gnome-vfs2 returned escaped file paths. If a     path, as stored in the URI, contained non- ASCII     characters or ASCII characters which are parsed as     something other than a file path (for example, spaces),     the escaped path was inaccurate. Consequently, files     with the described type of URI could not be processed.
    With this update, gnome-vfs2 properly unescapes paths     that are required for a system call. As a result, these     paths are parsed properly.

  - In certain cases, the trash info file was populated by     foreign entries, pointing to live data. Emptying the     trash caused an accidental deletion of valuable data.
    With this update, a workaround has been applied in order     to prevent the deletion. As a result, the accidental     data loss is prevented, however further information is     still gathered to fully fix this problem.

  - Due to a wrong test checking for a destination file     system, the Nautilus file manager failed to delete a     symbolic link to a folder which was residing in another     file system. With this update, a special test has been     added. As a result, a symbolic link pointing to another     file system can be trashed or deleted properly.

  - Prior to this update, when directories without a read     permission were marked for copy, the Nautilus file     manager skipped these unreadable directories without     notification. With this update, Nautilus displays an     error message and properly informs the user about the     aforementioned problem.

  - Previously, gnome-vfs2 used the stat() function calls     for every file on the MultiVersion File System (MVFS),     used for example by IBM Rational ClearCase. This     behavior significantly slowed down file operations. With     this update, the unnecessary stat() operations have been     limited. As a result, gnome-vfs2 user interfaces, such     as Nautilus, are more responsive.

Updated gnome-vfs2 packages that fix one security issue and several bugs are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low 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 gnome-vfs2 packages provide the GNOME Virtual File System, which is the foundation of the Nautilus file manager. neon is an HTTP and WebDAV client library embedded in the gnome-vfs2 packages.

A denial of service flaw was found in the neon Extensible Markup Language (XML) parser. Visiting a malicious DAV server with an application using gnome-vfs2 (such as Nautilus) could possibly cause the application to consume an excessive amount of CPU and memory.
(CVE-2009-2473)

This update also fixes the following bugs :

* When extracted from the Uniform Resource Identifier (URI), gnome-vfs2 returned escaped file paths. If a path, as stored in the URI, contained non-ASCII characters or ASCII characters which are parsed as something other than a file path (for example, spaces), the escaped path was inaccurate. Consequently, files with the described type of URI could not be processed. With this update, gnome-vfs2 properly unescapes paths that are required for a system call. As a result, these paths are parsed properly. (BZ#580855)

* In certain cases, the trash info file was populated by foreign entries, pointing to live data. Emptying the trash caused an accidental deletion of valuable data. With this update, a workaround has been applied in order to prevent the deletion. As a result, the accidental data loss is prevented, however further information is still gathered to fully fix this problem. (BZ#586015)

* Due to a wrong test checking for a destination file system, the Nautilus file manager failed to delete a symbolic link to a folder which was residing in another file system. With this update, a special test has been added. As a result, a symbolic link pointing to another file system can be trashed or deleted properly. (BZ#621394)

* Prior to this update, when directories without a read permission were marked for copy, the Nautilus file manager skipped these unreadable directories without notification. With this update, Nautilus displays an error message and properly informs the user about the aforementioned problem. (BZ#772307)

* Previously, gnome-vfs2 used the stat() function calls for every file on the MultiVersion File System (MVFS), used for example by IBM Rational ClearCase. This behavior significantly slowed down file operations. With this update, the unnecessary stat() operations have been limited. As a result, gnome-vfs2 user interfaces, such as Nautilus, are more responsive. (BZ#822817)

All gnome-vfs2 users are advised to upgrade to these updated packages, which contain backported patches to correct these issues.

CVE-2009-2473 neon, gnome-vfs2 embedded neon: billion laughs DoS attack

CVE-2009-2474 neon: Improper verification of x509v3 certificate with NULL (zero) byte in certain fields

It was discovered that neon is affected by the previously published 'null prefix attack', caused by incorrect handling of NULL characters in X.509 certificates. If an attacker is able to get a carefully-crafted certificate signed by a trusted Certificate Authority, the attacker could use the certificate during a man-in-the-middle attack and potentially confuse an application using the neon library into accepting it by mistake. (CVE-2009-2474)

A denial of service flaw was found in the neon Extensible Markup Language (XML) parser. A remote attacker (malicious DAV server) could provide a specially crafted XML document that would cause excessive memory and CPU consumption if an application using the neon XML parser was tricked into processing it. (CVE-2009-2473)

Applications using the neon HTTP and WebDAV client library, such as cadaver, must be restarted for this update to take effect.

Versions of Mac OS X 10.6 earlier than 10.6.5 are potentially affected by multiple vulnerabilities.  Mac OS X 10.6.5 contains security fixes for the following products :

  - AFP Server

  - Apache mod_perl

  - Apache

  - AppKit

  - ATS

  - CFNetwork

  - CoreGraphics

  - CoreText

  - CUPS

  - Directory Services

  - diskdev_cmds

Disk Images

  - Flash Player plug-in

  - gzip

  - Image Capture

  - ImageIO

  - Image RAW

  - Kernel

  - MySQL

  - neon

  - Networking

  - OpenLDAP

  - OpenSSL

  - Password Server

  - PHP

  - Printing

  - python

  - QuickLook

  - QuickTime

  - Safari RSS

  - Time Machine

  - Wiki Server

  - X11

  - xar

The remote host is running a version of Mac OS X 10.6.x that is prior to 10.6.5.

Mac OS X 10.6.5 contains security fixes for the following products :

  - AFP Server
  - Apache mod_perl
  - Apache
  - AppKit
  - ATS
  - CFNetwork
  - CoreGraphics
  - CoreText
  - CUPS
  - Directory Services
  - diskdev_cmds
  - Disk Images
  - Flash Player plug-in
  - gzip
  - Image Capture
  - ImageIO
  - Image RAW
  - Kernel
  - MySQL
  - neon
  - Networking
  - OpenLDAP
  - OpenSSL
  - Password Server
  - PHP
  - Printing
  - python
  - QuickLook
  - QuickTime
  - Safari RSS
  - Time Machine
  - Wiki Server
  - X11
  - xar

neon did not properly handle embedded NUL characters in X.509 certificates when comparing host names. Attackers could exploit that to spoof SSL servers. (CVE-2009-2408)

Specially crafted XML documents that contain a large number of nested entity references could cause neon to consume large amounts of CPU and memory. (CVE-2009-2473)

Updated neon packages that fix two security issues are now available for Red Hat Enterprise Linux 4 and 5.

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

neon is an HTTP and WebDAV client library, with a C interface. It provides a high-level interface to HTTP and WebDAV methods along with a low-level interface for HTTP request handling. neon supports persistent connections, proxy servers, basic, digest and Kerberos authentication, and has complete SSL support.

It was discovered that neon is affected by the previously published 'null prefix attack', caused by incorrect handling of NULL characters in X.509 certificates. If an attacker is able to get a carefully-crafted certificate signed by a trusted Certificate Authority, the attacker could use the certificate during a man-in-the-middle attack and potentially confuse an application using the neon library into accepting it by mistake. (CVE-2009-2474)

A denial of service flaw was found in the neon Extensible Markup Language (XML) parser. A remote attacker (malicious DAV server) could provide a specially crafted XML document that would cause excessive memory and CPU consumption if an application using the neon XML parser was tricked into processing it. (CVE-2009-2473)

All neon users should upgrade to these updated packages, which contain backported patches to correct these issues. Applications using the neon HTTP and WebDAV client library, such as cadaver, must be restarted for this update to take effect.

neon did not properly handle embedded NUL characters in X.509 certificates when comparing host names. Attackers could exploit that to spoof SSL servers (CVE-2009-2408).

Specially crafted XML documents that contain a large number of nested entity references could cause neon to consume large amounts of CPU and memory (CVE-2009-2473).

Multiple vulnerabilities has been found and corrected in libneon0.27 :

neon before 0.28.6, when expat is used, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564 (CVE-2009-2473).

neon before 0.28.6, when OpenSSL is used, does not properly handle a '&#0;' (NUL) character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408 (CVE-2009-2474).

This update provides a solution to these vulnerabilities.

This update includes the latest release of neon, version 0.28.6. This fixes two security issues: * the 'billion laughs' attack against expat could allow a Denial of Service attack by a malicious server.
(CVE-2009-2473) * an embedded NUL byte in a certificate subject name could allow an undetected MITM attack against an SSL server if a trusted CA issues such a cert.

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.

This update includes the latest release of neon, version 0.28.6. This fixes two security issues: * the 'billion laughs' attack against expat could allow a Denial of Service attack by a malicious server.
(CVE-2009-2473) * an embedded NUL byte in a certificate subject name could allow an undetected MITM attack against an SSL server if a trusted CA issues such a cert. Several bug fixes are also included, notably: * X.509v1 CA certificates are trusted by default * Fix handling of some PKCS#12 certificates

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.

ID	Name	Product	Family	Severity
198388	RHEL 4 : gnome-vfs2 (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	high
68702	Oracle Linux 5 : gnome-vfs2 (ELSA-2013-0131)	Nessus	Oracle Linux Local Security Checks	medium
67927	Oracle Linux 5 : neon (ELSA-2009-1452)	Nessus	Oracle Linux Local Security Checks	high
63594	Scientific Linux Security Update : gnome-vfs2 on SL5.x i386/x86_64 (20130108)	Nessus	Scientific Linux Local Security Checks	medium
63576	CentOS 5 : gnome-vfs2 (CESA-2013:0131)	Nessus	CentOS Local Security Checks	medium
63412	RHEL 5 : gnome-vfs2 (RHSA-2013:0131)	Nessus	Red Hat Local Security Checks	medium
60667	Scientific Linux Security Update : neon on SL4.x, SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
5705	Mac OS X 10.6 < 10.6.5 Multiple Vulnerabilities	Nessus Network Monitor	Generic	critical
50548	Mac OS X 10.6.x < 10.6.5 Multiple Vulnerabilities	Nessus	MacOS X Local Security Checks	critical
49905	SuSE 10 Security Update : neon (ZYPP Patch Number 6549)	Nessus	SuSE Local Security Checks	medium
43792	CentOS 4 / 5 : neon (CESA-2009:1452)	Nessus	CentOS Local Security Checks	medium
42324	openSUSE 10 Security Update : libneon-devel (libneon-devel-6550)	Nessus	SuSE Local Security Checks	medium
42317	openSUSE Security Update : libneon-devel (libneon-devel-1377)	Nessus	SuSE Local Security Checks	medium
42315	openSUSE Security Update : libneon-devel (libneon-devel-1377)	Nessus	SuSE Local Security Checks	medium
42303	SuSE 10 Security Update : neon (ZYPP Patch Number 6548)	Nessus	SuSE Local Security Checks	medium
42301	SuSE 11 Security Update : libneon (SAT Patch Number 1376)	Nessus	SuSE Local Security Checks	medium
41031	RHEL 4 / 5 : neon (RHSA-2009:1452)	Nessus	Red Hat Local Security Checks	medium
40764	Mandriva Linux Security Advisory : libneon0.27 (MDVSA-2009:221)	Nessus	Mandriva Local Security Checks	medium
40683	Fedora 11 : neon-0.28.6-1.fc11 (2009-8815)	Nessus	Fedora Local Security Checks	medium
40677	Fedora 10 : neon-0.28.6-1.fc10 (2009-8794)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2009-2473

high

Tenable Plugins

high

medium

high

medium

medium

medium

medium

critical

critical

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium