Algorithmic complexity vulnerability in the regular expression parser in TCL before 8.4.17, as used in PostgreSQL 8.2 before 8.2.6, 8.1 before 8.1.11, 8.0 before 8.0.15, and 7.4 before 7.4.19, allows remote authenticated users to cause a denial of service (memory consumption) via a crafted "complex" regular expression with doubly-nested states.

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

  - postgresql: tempory DoS caused by slow regex NFA cleanup (CVE-2007-6067)

  - The regular expression parser in TCL before 8.4.17, as used in PostgreSQL 8.2 before 8.2.6, 8.1 before     8.1.11, 8.0 before 8.0.15, and 7.4 before 7.4.19, allows context-dependent attackers to cause a denial of     service (infinite loop) via a crafted regular expression. (CVE-2007-4772)

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

From Red Hat Security Advisory 2013:0122 :

Updated tcl packages that fix two security issues and one bug are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate 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.

Tcl (Tool Command Language) provides a powerful platform for creating integration applications that tie together diverse applications, protocols, devices, and frameworks. When paired with the Tk toolkit, Tcl provides a fast and powerful way to create cross-platform GUI applications.

Two denial of service flaws were found in the Tcl regular expression handling engine. If Tcl or an application using Tcl processed a specially crafted regular expression, it would lead to excessive CPU and memory consumption. (CVE-2007-4772, CVE-2007-6067)

This update also fixes the following bug :

* Due to a suboptimal implementation of threading in the current version of the Tcl language interpreter, an attempt to use threads in combination with fork in a Tcl script could cause the script to stop responding. At the moment, it is not possible to rewrite the source code or drop support for threading entirely. Consequent to this, this update provides a version of Tcl without threading support in addition to the standard version with this support. Users who need to use fork in their Tcl scripts and do not require threading can now switch to the version without threading support by using the alternatives command. (BZ#478961)

All users of Tcl 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-2008-0038 advisory.

    [7.4.19-1.el4_6.1]
     - Update to PostgreSQL 7.4.19 to fix CVE-2007-4769, CVE-2007-4772,        CVE-2007-6067, CVE-2007-6600, CVE-2007-6601      Resolves: #427135

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.

Two denial of service flaws were found in the Tcl regular expression handling engine. If Tcl or an application using Tcl processed a specially crafted regular expression, it would lead to excessive CPU and memory consumption. (CVE-2007-4772, CVE-2007-6067)

This update also fixes the following bug :

  - Due to a suboptimal implementation of threading in the     current version of the Tcl language interpreter, an     attempt to use threads in combination with fork in a Tcl     script could cause the script to stop responding. At the     moment, it is not possible to rewrite the source code or     drop support for threading entirely. Consequent to this,     this update provides a version of Tcl without threading     support in addition to the standard version with this     support. Users who need to use fork in their Tcl scripts     and do not require threading can now switch to the     version without threading support by using the     alternatives command.

Updated tcl packages that fix two security issues and one bug are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate 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.

Tcl (Tool Command Language) provides a powerful platform for creating integration applications that tie together diverse applications, protocols, devices, and frameworks. When paired with the Tk toolkit, Tcl provides a fast and powerful way to create cross-platform GUI applications.

Two denial of service flaws were found in the Tcl regular expression handling engine. If Tcl or an application using Tcl processed a specially crafted regular expression, it would lead to excessive CPU and memory consumption. (CVE-2007-4772, CVE-2007-6067)

This update also fixes the following bug :

* Due to a suboptimal implementation of threading in the current version of the Tcl language interpreter, an attempt to use threads in combination with fork in a Tcl script could cause the script to stop responding. At the moment, it is not possible to rewrite the source code or drop support for threading entirely. Consequent to this, this update provides a version of Tcl without threading support in addition to the standard version with this support. Users who need to use fork in their Tcl scripts and do not require threading can now switch to the version without threading support by using the alternatives command. (BZ#478961)

All users of Tcl are advised to upgrade to these updated packages, which contain backported patches to correct these issues.

Will Drewry discovered multiple flaws in PostgreSQL's regular expression engine. An authenticated attacker could use these flaws to cause a denial of service by causing the PostgreSQL server to crash, enter an infinite loop, or use extensive CPU and memory resources while processing queries containing specially crafted regular expressions. Applications that accept regular expressions from untrusted sources may expose this problem to unauthorized attackers.
(CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)

A privilege escalation flaw was discovered in PostgreSQL. An authenticated attacker could create an index function that would be executed with administrator privileges during database maintenance tasks, such as database vacuuming. (CVE-2007-6600)

A privilege escalation flaw was discovered in PostgreSQL's Database Link library (dblink). An authenticated attacker could use dblink to possibly escalate privileges on systems with 'trust' or 'ident' authentication configured. Please note that dblink functionality is not enabled by default, and can only by enabled by a database administrator on systems with the postgresql-contrib package installed. (CVE-2007-3278, CVE-2007-6601)

This version update to 8.1.11 fixes among other things, several security issues :

  - Index Functions Privilege Escalation: CVE-2007-6600

  - Regular Expression Denial-of-Service: CVE-2007-4772,     CVE-2007-6067, CVE-2007-4769

  - DBLink Privilege Escalation: CVE-2007-6601

Index Functions Privilege Escalation (CVE-2007-6600): as a unique feature, PostgreSQL allows users to create indexes on the results of user-defined functions, known as expression indexes. This provided two vulnerabilities to privilege escalation: (1) index functions were executed as the superuser and not the table owner during VACUUM and ANALYZE, and (2) that SET ROLE and SET SESSION AUTHORIZATION were permitted within index functions.

Regular Expression Denial-of-Service (CVE-2007-4772, CVE-2007-6067, CVE-2007-4769): three separate issues in the regular expression libraries used by PostgreSQL allowed malicious users to initiate a denial-of-service by passing certain regular expressions in SQL queries. First, users could create infinite loops using some specific regular expressions. Second, certain complex regular expressions could consume excessive amounts of memory. Third, out-of-range backref numbers could be used to crash the backend.

DBLink Privilege Escalation (CVE-2007-6601): DBLink functions combined with local trust or ident authentication could be used by a malicious user to gain superuser privileges. This issue has been fixed, and does not affect users who have not installed DBLink (an optional module), or who are using password authentication for local access. This same problem was addressed in the previous release cycle (see CVE-2007-3278), but that patch failed to close all forms of the loophole.

Updated packages fix these issues by upgrading to the latest maintenance versions of PostgreSQL.

The PostgreSQL developers report :

PostgreSQL allows users to create indexes on the results of user-defined functions, known as 'expression indexes'. This provided two vulnerabilities to privilege escalation: (1) index functions were executed as the superuser and not the table owner during VACUUM and ANALYZE, and (2) that SET ROLE and SET SESSION AUTHORIZATION were permitted within index functions. Both of these holes have now been closed.

PostgreSQL allowed malicious users to initiate a denial-of-service by passing certain regular expressions in SQL queries. First, users could create infinite loops using some specific regular expressions. Second, certain complex regular expressions could consume excessive amounts of memory. Third, out-of-range backref numbers could be used to crash the backend.

DBLink functions combined with local trust or ident authentication could be used by a malicious user to gain superuser privileges. This issue has been fixed, and does not affect users who have not installed DBLink (an optional module), or who are using password authentication for local access. This same problem was addressed in the previous release cycle, but that patch failed to close all forms of the loophole.

This version update to 8.2.6 fixes among other things several security issues :

  - Index Functions Privilege Escalation: CVE-2007-6600

  - Regular Expression Denial-of-Service: CVE-2007-4772,     CVE-2007-6067, CVE-2007-4769

  - DBLink Privilege Escalation: CVE-2007-6601

This version update to 7.4.19 fixes among other things several security issues :

  - Index Functions Privilege Escalation: CVE-2007-6600

  - Regular Expression Denial-of-Service: CVE-2007-4772 /     CVE-2007-6067 / CVE-2007-4769

  - DBLink Privilege Escalation: CVE-2007-6601

This version update to 8.1.11 fixes among other things several security issues :

  - Index Functions Privilege Escalation: CVE-2007-6600

  - Regular Expression Denial-of-Service: CVE-2007-4772,     CVE-2007-6067, CVE-2007-4769

  - DBLink Privilege Escalation: CVE-2007-6601

The remote host is affected by the vulnerability described in GLSA-200801-15 (PostgreSQL: Multiple vulnerabilities)

    If using the 'expression indexes' feature, PostgreSQL executes index     functions as the superuser during VACUUM and ANALYZE instead of the     table owner, and allows SET ROLE and SET SESSION AUTHORIZATION in the     index functions (CVE-2007-6600). Additionally, several errors involving     regular expressions were found (CVE-2007-4769, CVE-2007-4772,     CVE-2007-6067). Eventually, a privilege escalation vulnerability via     unspecified vectors in the DBLink module was reported (CVE-2007-6601).
    This vulnerability is exploitable when local trust or ident     authentication is used, and is due to an incomplete fix of     CVE-2007-3278.
  Impact :

    A remote authenticated attacker could send specially crafted queries     containing complex regular expressions to the server that could result     in a Denial of Service by a server crash (CVE-2007-4769), an infinite     loop (CVE-2007-4772) or a memory exhaustion (CVE-2007-6067). The two     other vulnerabilities can be exploited to gain additional privileges.
  Workaround :

    There is no known workaround for all these issues at this time.

Nico Leidecker discovered that PostgreSQL did not properly restrict dblink functions. An authenticated user could exploit this flaw to access arbitrary accounts and execute arbitrary SQL queries.
(CVE-2007-3278, CVE-2007-6601)

It was discovered that the TCL regular expression parser used by PostgreSQL did not properly check its input. An attacker could send crafted regular expressions to PostgreSQL and cause a denial of service via resource exhaustion or database crash. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)

It was discovered that PostgreSQL executed VACUUM and ANALYZE operations within index functions with superuser privileges and also allowed SET ROLE and SET SESSION AUTHORIZATION within index functions.
A remote authenticated user could exploit these flaws to gain privileges. (CVE-2007-6600).

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 local vulnerabilities have been discovered in PostgreSQL, an object-relational SQL database. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2007-3278     It was discovered that the DBLink module performed     insufficient credential validation. This issue is also     tracked as CVE-2007-6601, since the initial upstream fix     was incomplete.

  - CVE-2007-4769     Tavis Ormandy and Will Drewry discovered that a bug in     the handling of back-references inside the regular     expressions engine could lead to an out of bounds read,     resulting in a crash. This constitutes only a security     problem if an application using PostgreSQL processes     regular expressions from untrusted sources.

  - CVE-2007-4772     Tavis Ormandy and Will Drewry discovered that the     optimizer for regular expression could be tricked into     an infinite loop, resulting in denial of service. This     constitutes only a security problem if an application     using PostgreSQL processes regular expressions from     untrusted sources.

  - CVE-2007-6067     Tavis Ormandy and Will Drewry discovered that the     optimizer for regular expression could be tricked     massive resource consumption. This constitutes only a     security problem if an application using PostgreSQL     processes regular expressions from untrusted sources.

  - CVE-2007-6600     Functions in index expressions could lead to privilege     escalation. For a more in depth explanation please see     the upstream announce available at     http://www.postgresql.org/about/news.905.

Updated postgresql packages that fix several 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.

PostgreSQL is an advanced Object-Relational database management system (DBMS). The postgresql packages include the client programs and libraries needed to access a PostgreSQL DBMS server.

Will Drewry discovered multiple flaws in PostgreSQL's regular expression engine. An authenticated attacker could use these flaws to cause a denial of service by causing the PostgreSQL server to crash, enter an infinite loop, or use extensive CPU and memory resources while processing queries containing specially crafted regular expressions. Applications that accept regular expressions from untrusted sources may expose this problem to unauthorized attackers.
(CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)

A privilege escalation flaw was discovered in PostgreSQL. An authenticated attacker could create an index function that would be executed with administrator privileges during database maintenance tasks, such as database vacuuming. (CVE-2007-6600)

A privilege escalation flaw was discovered in PostgreSQL's Database Link library (dblink). An authenticated attacker could use dblink to possibly escalate privileges on systems with 'trust' or 'ident' authentication configured. Please note that dblink functionality is not enabled by default, and can only by enabled by a database administrator on systems with the postgresql-contrib package installed. (CVE-2007-3278, CVE-2007-6601)

All postgresql users should upgrade to these updated packages, which include PostgreSQL 7.4.19 and 8.1.11, and resolve these issues.

- Mon Jan 7 2008 Tom Lane <tgl at redhat.com> 8.2.6-1

    - Update to PostgreSQL 8.2.6 to fix CVE-2007-4769,       CVE-2007-4772, CVE-2007-6067, CVE-2007-6600,       CVE-2007-6601

  - Make initscript and pam config files be installed     unconditionally; seems new buildroots don't necessarily     have those directories in place

  - Thu Sep 20 2007 Tom Lane <tgl at redhat.com> 8.2.5-1

    - Update to PostgreSQL 8.2.5 and pgtcl 1.6.0

    - Fix multilib problem for /usr/include/ecpg_config.h       (which is new in 8.2.x)

    - Use tzdata package's data files instead of private       copy, so that postgresql-server need not be turned for       routine timezone updates

  - Don't remove postgres user/group during RPM uninstall,     per Fedora packaging guidelines

  - Recent perl changes in rawhide mean we need a more     specific BuildRequires

    - Wed Jun 20 2007 Tom Lane <tgl at redhat.com> 8.2.4-2

    - Fix oversight in postgresql-test makefile: pg_regress       isn't a shell script anymore. Per upstream bug 3398.

  - Tue Apr 24 2007 Tom Lane <tgl at redhat.com> 8.2.4-1

    - Update to PostgreSQL 8.2.4 for CVE-2007-2138, data       loss bugs Resolves: #237682

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.

- Mon Jan 7 2008 Tom Lane <tgl at redhat.com> 8.2.6-1

    - Update to PostgreSQL 8.2.6 to fix CVE-2007-4769,       CVE-2007-4772, CVE-2007-6067, CVE-2007-6600,       CVE-2007-6601

  - Make initscript and pam config files be installed     unconditionally; seems new buildroots don't necessarily     have those directories in place

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.

The remote host is running PostgreSQL, an open source relational database.  This version is vulnerable to six distinct remote flaws.  The nature of three of these flaws involves privilege escalation.  An attacker exploiting the 'privilege escalation' bugs would either need local access or user credentials in order to elevate their access.  The other three flaws involve remote denial of service attacks.  An attacker exploiting these flaws would not need any sort of credentials and would have the ability to crash the database service.  

ID	Name	Product	Family	Severity
198405	RHEL 4 : tcl (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
68693	Oracle Linux 5 : tcl (ELSA-2013-0122)	Nessus	Oracle Linux Local Security Checks	medium
67638	Oracle Linux 5 : Moderate: / postgresql (ELSA-2008-0038)	Nessus	Oracle Linux Local Security Checks	critical
63605	Scientific Linux Security Update : tcl on SL5.x i386/x86_64 (20130108)	Nessus	Scientific Linux Local Security Checks	medium
63567	CentOS 5 : tcl (CESA-2013:0122)	Nessus	CentOS Local Security Checks	medium
63405	RHEL 5 : tcl (RHSA-2013:0122)	Nessus	Red Hat Local Security Checks	medium
60343	Scientific Linux Security Update : postgresql on SL3.x, SL4.x, SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
41193	SuSE9 Security Update : postgresql (YOU Patch Number 12065)	Nessus	SuSE Local Security Checks	high
38083	Mandriva Linux Security Advisory : postgresql (MDVSA-2008:004)	Nessus	Mandriva Local Security Checks	high
32063	FreeBSD : postgresql -- multiple vulnerabilities (51436b4c-1250-11dd-bab7-0016179b2dd5)	Nessus	FreeBSD Local Security Checks	high
30251	openSUSE 10 Security Update : postgresql (postgresql-4955)	Nessus	SuSE Local Security Checks	medium
30199	SuSE 10 Security Update : PostgreSQL (ZYPP Patch Number 4962)	Nessus	SuSE Local Security Checks	high
30198	openSUSE 10 Security Update : postgresql (postgresql-4958)	Nessus	SuSE Local Security Checks	medium
30120	GLSA-200801-15 : PostgreSQL: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
29978	Ubuntu 6.06 LTS / 6.10 / 7.04 / 7.10 : postgresql vulnerabilities (USN-568-1)	Nessus	Ubuntu Local Security Checks	high
29968	Debian DSA-1463-1 : postgresql-7.4 - several vulnerabilities	Nessus	Debian Local Security Checks	high
29955	RHEL 4 / 5 : postgresql (RHSA-2008:0038)	Nessus	Red Hat Local Security Checks	high
29948	Fedora 7 : postgresql-8.2.6-1.fc7 (2008-0552)	Nessus	Fedora Local Security Checks	high
29944	Fedora 8 : postgresql-8.2.6-1.fc8 (2008-0478)	Nessus	Fedora Local Security Checks	high
29937	Debian DSA-1460-1 : postgresql-8.1 - several vulnerabilities	Nessus	Debian Local Security Checks	high
29933	CentOS 4 / 5 : postgresql (CESA-2008:0038)	Nessus	CentOS Local Security Checks	high
4333	PostgreSQL Multiple Vulnerabilities	Nessus Network Monitor	Database	high

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CVE-2007-6067

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