OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.

Two vulnerabilities were discovered in openssl, an implementation of the SSL protocol, using the Codenomicon TLS Test Tool. More information can be found in the following NISCC Vulnerability Advisory and this OpenSSL advisory. The Common Vulnerabilities and Exposures project identified the following vulnerabilities :

  - CAN-2004-0079     NULL pointer assignment in the do_change_cipher_spec()     function. A remote attacker could perform a carefully     crafted SSL/TLS handshake against a server that used the     OpenSSL library in such a way as to cause OpenSSL to     crash. Depending on the application this could lead to a     denial of service.

  - CAN-2004-0081

    A bug in older versions of OpenSSL 0.9.6 that can lead     to a Denial of Service attack (infinite loop).

The remote host is using a version of OpenSSL that is older than 0.9.6m or 0.9.7d  There are several vulnerabilities in this version of OpenSSL that may allow an attacker to cause a denial of service against the remote host.

The remote host is affected by the vulnerability described in GLSA-200403-03 (Multiple OpenSSL Vulnerabilities)

    Testing performed by the OpenSSL group using the Codenomicon TLS Test     Tool uncovered a NULL pointer assignment in the do_change_cipher_spec()     function. A remote attacker could perform a carefully crafted SSL/TLS     handshake against a server that used the OpenSSL library in such a way     as to cause OpenSSL to crash. Depending on the application this could     lead to a denial of service. All versions of OpenSSL from 0.9.6c to     0.9.6l inclusive and from 0.9.7a to 0.9.7c inclusive are affected by     this issue.
    A flaw has been discovered in SSL/TLS handshaking code when using     Kerberos ciphersuites. A remote attacker could perform a carefully     crafted SSL/TLS handshake against a server configured to use Kerberos     ciphersuites in such a way as to cause OpenSSL to crash. Most     applications have no ability to use Kerberos cipher suites and will     therefore be unaffected. Versions 0.9.7a, 0.9.7b, and 0.9.7c of OpenSSL     are affected by this issue.
    Testing performed by the OpenSSL group using the Codenomicon TLS Test     Tool uncovered a bug in older versions of OpenSSL 0.9.6 that can lead     to a Denial of Service attack (infinite loop). This issue was traced to     a fix that was added to OpenSSL 0.9.6d some time ago. This issue will     affect vendors that ship older versions of OpenSSL with backported     security patches.
  Impact :

    Although there are no public exploits known for bug, users are     recommended to upgrade to ensure the security of their infrastructure.
  Workaround :

    There is no immediate workaround; a software upgrade is required. The     vulnerable function in the code has been rewritten.

This update includes OpenSSL packages to fix two security issues affecting OpenSSL 0.9.7a which allow denial of service attacks;
CVE-2004-0079 and CVE-2003-0851.

Also included are updates for the OpenSSL 0.9.6 and 0.9.6b compatibility libraries included in Fedora Core 1, fixing a separate issue which could also lead to a denial of service attack;
CVE-2004-0081.

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.

Updated OpenSSL packages that fix several remote denial of service vulnerabilities are available for Red Hat Enterprise Linux 3.

The OpenSSL toolkit implements Secure Sockets Layer (SSL v2/v3), Transport Layer Security (TLS v1) protocols, and serves as a full-strength general purpose cryptography library.

Testing performed by the OpenSSL group using the Codenomicon TLS Test Tool uncovered a NULL pointer assignment in the do_change_cipher_spec() function in OpenSSL 0.9.6c-0.9.6k and 0.9.7a-0.9.7c. A remote attacker could perform a carefully crafted SSL/TLS handshake against a server that uses the OpenSSL library in such a way as to cause OpenSSL to crash. Depending on the application this could lead to a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0079 to this issue.

Stephen Henson discovered a flaw in SSL/TLS handshaking code when using Kerberos ciphersuites in OpenSSL 0.9.7a-0.9.7c. A remote attacker could perform a carefully crafted SSL/TLS handshake against a server configured to use Kerberos ciphersuites in such a way as to cause OpenSSL to crash. Most applications have no ability to use Kerberos ciphersuites and will therefore be unaffected by this issue.
The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0112 to this issue.

Testing performed by the OpenSSL group using the Codenomicon TLS Test Tool uncovered a bug in older versions of OpenSSL 0.9.6 prior to 0.9.6d that may lead to a denial of service attack (infinite loop).
The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0081 to this issue. This issue affects only the OpenSSL compatibility packages shipped with Red Hat Enterprise Linux 3.

These updated packages contain patches provided by the OpenSSL group that protect against these issues.

Additionally, the version of libica included in the OpenSSL packages has been updated to 1.3.5. This only affects IBM s390 and IBM eServer zSeries customers and is required for the latest openCryptoki packages.

NOTE: Because server applications are affected by this issue, users are advised to either restart all services that use OpenSSL functionality or restart their systems after installing these updates.

Updated OpenSSL packages that fix a remote denial of service vulnerability are now available for Red Hat Enterprise Linux 2.1.

OpenSSL is a toolkit that implements Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library.

Testing performed by the OpenSSL group using the Codenomicon TLS Test Tool uncovered a bug in older versions of OpenSSL 0.9.6 prior to 0.9.6d that can lead to a denial of service attack (infinite loop).
The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0081 to this issue.

Testing performed by Novell using a test suite provided by NISCC uncovered an issue in the ASN.1 parser in versions of OpenSSL 0.9.6 prior to 0.9.6l which could cause large recursion and possibly lead to a denial of service attack if used where stack space is limited. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0851 to this issue.

These updated packages contain patches provided by the OpenSSL group that protect against these issues.

NOTE: Because server applications are affected by this issue, users are advised to either restart all services using OpenSSL functionality or restart their system after installing these updated packages.

According to its banner, the remote host is using a version of OpenSSL which is older than 0.9.6m / 0.9.7d.  There are several bugs in such versions that may allow an attacker to cause a denial of service against the remote host.

ID	Name	Product	Family	Severity
15302	Debian DSA-465-1 : openssl - several vulnerabilities	Nessus	Debian Local Security Checks	medium
2183	OpenSSL < 0.9.6m / 0.9.7d Multiple DoS	Nessus Network Monitor	Web Servers	medium
14454	GLSA-200403-03 : Multiple OpenSSL Vulnerabilities	Nessus	Gentoo Local Security Checks	medium
13684	Fedora Core 1 : openssl-0.9.7a-33.10 (2004-095)	Nessus	Fedora Local Security Checks	medium
12480	RHEL 3 : openssl (RHSA-2004:120)	Nessus	Red Hat Local Security Checks	medium
12479	RHEL 2.1 : openssl (RHSA-2004:119)	Nessus	Red Hat Local Security Checks	medium
12110	OpenSSL < 0.9.6m / 0.9.7d Multiple Remote DoS	Nessus	Web Servers	medium
801058	OpenSSL < 0.9.6m / 0.9.7d Multiple DoS	Log Correlation Engine	Web Servers	medium

Detections

Analytics

CVE-2004-0081

high

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium

medium