Race condition in shtool 2.0.1 and earlier allows local users to create or modify arbitrary files via a symlink attack on the .shtool.$$ temporary file, a different vulnerability than CVE-2005-1759.

Updated PHP packages that fix two security issues are now available.

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

PHP is an HTML-embedded scripting language commonly used with the Apache HTTP Web server.

A bug was discovered in the PEAR XML-RPC Server package included in PHP. If a PHP script is used which implements an XML-RPC Server using the PEAR XML-RPC package, then it is possible for a remote attacker to construct an XML-RPC request which can cause PHP to execute arbitrary PHP commands as the 'apache' user. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2005-1921 to this issue.

When using the default SELinux 'targeted' policy on Red Hat Enterprise Linux 4, the impact of this issue is reduced since the scripts executed by PHP are constrained within the httpd_sys_script_t security context.

A race condition in temporary file handling was discovered in the shtool script installed by PHP. If a third-party PHP module which uses shtool was compiled as root, a local user may be able to modify arbitrary files. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2005-1751 to this issue.

Users of PHP should upgrade to these updated packages, which contain backported fixes for these issues.

CAN-2005-1751 :

The php4-dev package ships a copy of the 'shtool' utility in /usr/lib/php4/build/, which provides useful functionality for developers of software packages. Eric Romang discovered that shtool created temporary files in an insecure manner. This could allow a symlink attack to create or overwrite arbitrary files with the privileges of the user invoking the shtool program.

CAN-1005-1759 :

The creation of temporary files in shtool was also vulnerable to a race condition which allowed a local user to read the contents of the temporary file. However, this file does not usually contain sensitive information since shtool is usually used for building software packages.

CAN-2005-2498 :

Stefan Esser discovered another remote code execution vulnerability in the XMLRPC module of the PEAR (PHP Extension and Application Repository) extension of PHP. By sending specially crafted XMLRPC requests to an affected web server, a remote attacker could exploit this to execute arbitrary code with the web server's privileges.

In Ubuntu, the PEAR extension is unsupported (it is contained in the php4-pear package which is part of universe). However, since this is a highly critical vulnerability, that package was fixed anyway.

Please note that many applications contain a copy of the affected XMLRPC code, which must be fixed separately. The following packages may also be affected, but are unsupported in Ubuntu :

  - drupal - wordpress - phpwiki - horde3 - ewiki -     egroupware - phpgroupware

    These packages might be fixed by the community later.

    The following common third-party applications might be     affected as well, but not packaged for Ubuntu :

  - Serendipity - Postnuke - tikiwiki - phpwebsite

    If you run any affected software, please check whether     you are affected and upgrade it as soon as possible to     protect your server.

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

Several security related problems have been found in PHP4, the server-side, HTML-embedded scripting language. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CAN-2005-1751     Eric Romang discovered insecure temporary files in the     shtool utility shipped with PHP that can exploited by a     local attacker to overwrite arbitrary files. Only this     vulnerability affects packages in oldstable.

  - CAN-2005-1921

    GulfTech has discovered that PEAR XML_RPC is vulnerable     to a remote PHP code execution vulnerability that may     allow an attacker to compromise a vulnerable server.

  - CAN-2005-2498

    Stefan Esser discovered another vulnerability in the     XML-RPC libraries that allows injection of arbitrary PHP     code into eval() statements.

A Zataz advisory reports that shtool contains a security flaw which could allow a malicious local user to create or overwrite the contents of arbitrary files. The attacker could fool a user into executing the arbitrary file possibly executing arbitrary code.

The remote Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:564 advisory.

    PHP is an HTML-embedded scripting language commonly used with the Apache     HTTP Web server.

    A bug was discovered in the PEAR XML-RPC Server package included in PHP.
    If a PHP script is used which implements an XML-RPC Server using the PEAR     XML-RPC package, then it is possible for a remote attacker to construct an     XML-RPC request which can cause PHP to execute arbitrary PHP commands as     the 'apache' user. The Common Vulnerabilities and Exposures project     (cve.mitre.org) has assigned the name CAN-2005-1921 to this issue.

    When using the default SELinux targeted policy on Red Hat Enterprise     Linux 4, the impact of this issue is reduced since the scripts executed by     PHP are constrained within the httpd_sys_script_t security context.

    A race condition in temporary file handling was discovered in the shtool     script installed by PHP.  If a third-party PHP module which uses shtool was     compiled as root, a local user may be able to modify arbitrary files.
    The Common Vulnerabilities and Exposures project (cve.mitre.org) has     assigned the name CAN-2005-1751 to this issue.

    Users of PHP should upgrade to these updated packages, which contain     backported fixes for these issues.

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

The remote host is affected by the vulnerability described in GLSA-200506-08 (GNU shtool, ocaml-mysql: Insecure temporary file creation)

    Eric Romang has discovered that GNU shtool insecurely creates     temporary files with predictable filenames (CAN-2005-1751). On closer     inspection, Gentoo Security discovered that the shtool temporary file,     once created, was being reused insecurely (CAN-2005-1759).
  Impact :

    A local attacker could create symbolic links in the temporary     files directory, pointing to a valid file somewhere on the filesystem.
    When a GNU shtool script is executed, this would result in the file     being overwritten with the rights of the user running the script, which     could be the root user.
  Workaround :

    There is no known workaround at this time.

ID	Name	Product	Family	Severity
21841	CentOS 3 / 4 : php (CESA-2005:564)	Nessus	CentOS Local Security Checks	high
20578	Ubuntu 4.10 / 5.04 : php4 vulnerabilities (USN-171-1)	Nessus	Ubuntu Local Security Checks	medium
19532	Debian DSA-789-1 : php4 - several vulnerabilities	Nessus	Debian Local Security Checks	high
18964	FreeBSD : shtool -- insecure temporary file creation (6596bb80-d026-11d9-9aed-000e0c2e438a)	Nessus	FreeBSD Local Security Checks	low
18648	RHEL 4 : php (RHSA-2005:564)	Nessus	Red Hat Local Security Checks	critical
18465	GLSA-200506-08 : GNU shtool, ocaml-mysql: Insecure temporary file creation	Nessus	Gentoo Local Security Checks	low

Detections

Analytics

CVE-2005-1751

medium

Tenable Plugins

high

medium

high

low

critical

low