Memory leak in a certain Red Hat deployment of vsftpd before 2.0.5 on Red Hat Enterprise Linux (RHEL) 3 and 4, when PAM is used, allows remote attackers to cause a denial of service (memory consumption) via a large number of invalid authentication attempts within the same session, a different vulnerability than CVE-2007-5962.

From Red Hat Security Advisory 2008:0579 :

An updated vsftpd package that fixes a security issue is now available.

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

vsftpd (Very Secure File Transfer Protocol (FTP) daemon) is a secure FTP server for Linux and Unix-like systems.

The version of vsftpd as shipped in Red Hat Enterprise Linux 3 when used in combination with Pluggable Authentication Modules (PAM) had a memory leak on an invalid authentication attempt. Since vsftpd prior to version 2.0.5 allows any number of invalid attempts on the same connection this memory leak could lead to an eventual DoS.
(CVE-2008-2375)

This update mitigates this security issue by including a backported patch which terminates a session after a given number of failed log in attempts. The default number of attempts is 3 and this can be configured using the 'max_login_fails' directive.

All vsftpd users should upgrade to this updated package, which addresses this vulnerability.

The version of vsftpd as shipped in Red Hat Enterprise Linux 4 when used in combination with Pluggable Authentication Modules (PAM) had a memory leak on an invalid authentication attempt. Since vsftpd prior to version 2.0.5 allows any number of invalid attempts on the same connection this memory leak could lead to an eventual DoS.
(CVE-2008-2375)

This update mitigates this security issue by including a backported patch which terminates a session after a given number of failed log in attempts. The default number of attempts is 3 and this can be configured using the 'max_login_fails' directive.

This package also addresses the following bugs :

  - when uploading unique files, a bug in vsftpd caused the     file to be saved with a suffix '.1' even when no     previous file with that name existed. This issues is     resolved in this package.

  - when vsftpd was run through the init script, it was     possible for the init script to print an 'OK' message,     even though the vsftpd may not have started. The init     script no longer produces a false verification with this     update.

  - vsftpd only supported usernames with a maximum length of     32 characters. The updated package now supports     usernames up to 128 characters long.

  - a system flaw meant vsftpd output could become dependent     on the timing or sequence of other events, even when the     'lock_upload_files' option was set. If a file,     filename.ext, was being uploaded and a second transfer     of the file, filename.ext, was started before the first     transfer was finished, the resultant uploaded file was a     corrupt concatenation of the latter upload and the tail     of the earlier upload. With this updated package, vsftpd     allows the earlier upload to complete before overwriting     with the latter upload, fixing the issue.

  - the 'lock_upload_files' option was not documented in the     manual page. A new manual page describing this option is     included in this package.

  - vsftpd did not support usernames that started with an     underscore or a period character. These special     characters are now allowed at the beginning of a     username.

  - when storing a unique file, vsftpd could cause an error     for some clients. This is rectified in this package.

  - vsftpd init script was found to not be Linux Standards     Base compliant. This update corrects their exit codes to     conform to the standard.

The version of vsftpd as shipped in Scientific Linux 3 when used in combination with Pluggable Authentication Modules (PAM) had a memory leak on an invalid authentication attempt. Since vsftpd prior to version 2.0.5 allows any number of invalid attempts on the same connection this memory leak could lead to an eventual DoS.
(CVE-2008-2375)

This update mitigates this security issue by including a backported patch which terminates a session after a given number of failed log in attempts. The default number of attempts is 3 and this can be configured using the 'max_login_fails' directive.

This update of vsftpd fixes a memory leak that can occur during authentication. (CVE-2008-2375) Additionally non-security bugs for SLES10 were fixed. There were some issues with simultaneous FTP PUT of the same file name that lead to a corrupted file on the server.

An updated vsftpd package that fixes a security issue is now available.

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

vsftpd (Very Secure File Transfer Protocol (FTP) daemon) is a secure FTP server for Linux and Unix-like systems.

The version of vsftpd as shipped in Red Hat Enterprise Linux 3 when used in combination with Pluggable Authentication Modules (PAM) had a memory leak on an invalid authentication attempt. Since vsftpd prior to version 2.0.5 allows any number of invalid attempts on the same connection this memory leak could lead to an eventual DoS.
(CVE-2008-2375)

This update mitigates this security issue by including a backported patch which terminates a session after a given number of failed log in attempts. The default number of attempts is 3 and this can be configured using the 'max_login_fails' directive.

All vsftpd users should upgrade to this updated package, which addresses this vulnerability.

The remote Redhat Enterprise Linux 4 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2008:0680 advisory.

    vsftpd (Very Secure File Transfer Protocol (FTP) daemon) is a secure FTP     server for Linux and Unix-like systems.

    The version of vsftpd as shipped in Red Hat Enterprise Linux 4 when used in     combination with Pluggable Authentication Modules (PAM) had a memory leak     on an invalid authentication attempt. Since vsftpd prior to version 2.0.5     allows any number of invalid attempts on the same connection this memory     leak could lead to an eventual DoS. (CVE-2008-2375)

    This update mitigates this security issue by including a backported patch     which terminates a session after a given number of failed log in attempts.
    The default number of attempts is 3 and this can be configured using the     max_login_fails directive.

    This package also addresses the following bugs:

    * when uploading unique files, a bug in vsftpd caused the file to be saved     with a suffix '.1' even when no previous file with that name existed. This     issues is resolved in this package.

    * when vsftpd was run through the init script, it was possible for the init     script to print an 'OK' message, even though the vsftpd may not have     started. The init script no longer produces a false verification with this     update.

    * vsftpd only supported usernames with a maximum length of 32 characters.
    The updated package now supports usernames up to 128 characters long.

    * a system flaw meant vsftpd output could become dependent on the timing or     sequence of other events, even when the lock_upload_files option was set.
    If a file, filename.ext, was being uploaded and a second transfer of the     file, filename.ext, was started before the first transfer was finished, the     resultant uploaded file was a corrupt concatenation of the latter upload     and the tail of the earlier upload. With this updated package, vsftpd     allows the earlier upload to complete before overwriting with the latter     upload, fixing the issue.

    * the 'lock_upload_files' option was not documented in the manual page. A     new manual page describing this option is included in this package.

    * vsftpd did not support usernames that started with an underscore or a     period character. These special characters are now allowed at the beginning     of a username.

    * when storing a unique file, vsftpd could cause an error for some clients.
    This is rectified in this package.

    * vsftpd init script was found to not be Linux Standards Base compliant.
    This update corrects their exit codes to conform to the standard.

    All vsftpd users are advised to upgrade to this updated package, which     resolves 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 this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
67721	Oracle Linux 3 : vsftpd (ELSA-2008-0579)	Nessus	Oracle Linux Local Security Checks	high
60456	Scientific Linux Security Update : vsftpd on SL4.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
60455	Scientific Linux Security Update : vsftpd on SL3.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
41220	SuSE9 Security Update : vsftpd (YOU Patch Number 12192)	Nessus	SuSE Local Security Checks	high
34079	SuSE 10 Security Update : vsftpd (ZYPP Patch Number 5388)	Nessus	SuSE Local Security Checks	high
33736	CentOS 3 : vsftpd (CESA-2008:0579)	Nessus	CentOS Local Security Checks	high
33582	RHEL 4 : vsftpd (RHSA-2008:0680)	Nessus	Red Hat Local Security Checks	high
33580	RHEL 3 : vsftpd (RHSA-2008:0579)	Nessus	Red Hat Local Security Checks	high

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CVE-2008-2375

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