CVS 1.11.x before 1.11.17, and 1.12.x before 1.12.9, allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.

A number of vulnerabilities were discovered in CVS by Stefan Esser, Sebastian Krahmer, and Derek Price.

- Insufficient input validation while processing 'Entry' lines.
(CVE-2004-0414)

- A double-free resulting from erroneous state handling while processing 'Argumentx' commands. (CVE-2004-0416)

- Integer overflow while processing 'Max-dotdot' commands.
(CVE-2004-0417)

- Erroneous handling of empty entries handled while processing 'Notify' commands. (CVE-2004-0418)

- A format string bug while processing CVS wrappers.

- Single-byte buffer underflows while processing configuration files from CVSROOT.

- Various other integer overflows.

Additionally, iDEFENSE reports an undocumented command-line flag used in debugging does not perform input validation on the given path names.

CVS servers ('cvs server' or :pserver: modes) are affected by these vulnerabilities. They vary in impact but include information disclosure (the iDEFENSE-reported bug), denial-of-service (CVE-2004-0414, CVE-2004-0416, CVE-2004-0417 and other bugs), or possibly arbitrary code execution (CVE-2004-0418). In very special situations where the attacker may somehow influence the contents of CVS configuration files in CVSROOT, additional attacks may be possible.

iDEFENSE discovered a flaw in CVS versions prior to 1.1.17 in an undocumented switch implemented in CVS' history command. The -X switch specifies the name of the history file which allows an attacker to determine whether arbitrary system files and directories exist and whether or not the CVS process has access to them.

This flaw has been fixed in CVS version 1.1.17.

Sebastian Krahmer and Stefan Esser discovered several vulnerabilities in the CVS server, which serves the popular Concurrent Versions System. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CAN-2004-0416: double-free() in error_prog_name
  - CAN-2004-0417: argument integer overflow

  - CAN-2004-0418: out of bound writes in serve_notify()

The remote CVS server, according to its version number, can be exploited by malicious users to gain knowledge of certain system information.

This behavior can be exploited to determine the existence and permissions of arbitrary files and directories on a vulnerable system.

The remote host is running a CVS server that, according to its version number, is vulnerable to an information disclosure issue. This weakness can be exploited by malicious users to gain knowledge about files and directories existing on the server.

An updated cvs package that fixes several server vulnerabilities, which could be exploited by a malicious client, is now available.

CVS is a version control system frequently used to manage source code repositories.

While investigating a previously fixed vulnerability, Derek Price discovered a flaw relating to malformed 'Entry' lines which lead to a missing NULL terminator. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0414 to this issue.

Stefan Esser and Sebastian Krahmer conducted an audit of CVS and fixed a number of issues that may have had security consequences.

Among the issues deemed likely to be exploitable were :

-- a double-free relating to the error_prog_name string (CVE-2004-0416) -- an argument integer overflow (CVE-2004-0417) -- out-of-bounds writes in serv_notify (CVE-2004-0418).

An attacker who has access to a CVS server may be able to execute arbitrary code under the UID on which the CVS server is executing.

Users of CVS are advised to upgrade to this updated package, which contains backported patches correcting these issues.

Red Hat would like to thank Stefan Esser, Sebastian Krahmer, and Derek Price for auditing, disclosing, and providing patches for these issues.

ID	Name	Product	Family	Severity
37427	FreeBSD : cvs -- numerous vulnerabilities (d2102505-f03d-11d8-81b0-000347a4fa7d)	Nessus	FreeBSD Local Security Checks	critical
15522	Mandrake Linux Security Advisory : cvs (MDKSA-2004:108)	Nessus	Mandriva Local Security Checks	medium
15356	Debian DSA-519-1 : cvs - several vulnerabilities	Nessus	Debian Local Security Checks	critical
14313	CVS history.c File Existence Information Disclosure	Nessus	Misc.	medium
2155	CVS history.c File Existence Disclosure	Nessus Network Monitor	Generic	medium
12500	RHEL 2.1 / 3 : cvs (RHSA-2004:233)	Nessus	Red Hat Local Security Checks	critical

Detections

Analytics

CVE-2004-0778

medium

Tenable Plugins

critical

medium

critical

medium

medium

critical