Buffer overflow in OpenSSL 0.9.7 before 0.9.7-beta3, with Kerberos enabled, allows attackers to execute arbitrary code via a long master key.

According to its banner, the remote server is running a version of OpenSSL that is earlier than 0.9.7-beta3. 

If Kerberos is enabled, a remote attacker could trigger a buffer overflow with a long master key and execute arbitrary code.

The OpenSSL development team has announced that a security audit by A.L. Digital Ltd and The Bunker, under the DARPA CHATS program, has revealed remotely exploitable buffer overflow conditions in the OpenSSL code. Additionally, the ASN1 parser in OpenSSL has a potential DoS attack independently discovered by Adi Stav and James Yonan.

CAN-2002-0655 references overflows in buffers used to hold ASCII representations of integers on 64 bit platforms. CAN-2002-0656 references buffer overflows in the SSL2 server implementation (by sending an invalid key to the server) and the SSL3 client implementation (by sending a large session id to the client). The SSL2 issue was also noticed by Neohapsis, who have privately demonstrated exploit code for this issue. CAN-2002-0659 references the ASN1 parser DoS issue.

These vulnerabilities have been addressed for Debian 3.0 (woody) in openssl094_0.9.4-6.woody.2, openssl095_0.9.5a-6.woody.1 and openssl_0.9.6c-2.woody.1.

These vulnerabilities are also present in Debian 2.2 (potato). Fixed packages are available in openssl094_0.9.4-6.potato.2 and openssl_0.9.6c-0.potato.4.

A worm is actively exploiting this issue on internet-attached hosts;
we recommend you upgrade your OpenSSL as soon as possible. Note that you must restart any daemons using SSL. (E.g., ssh or ssl-enabled apache.) If you are uncertain which programs are using SSL you may choose to reboot to ensure that all running daemons are using the new libraries.

An audit of the OpenSSL code by A.L. Digital Ltd and The Bunker, under the DARPA program CHATS, discovered a number of vulnerabilities in the OpenSSL code that are all potentially remotely exploitable.

From the OpenSSL advisory :

1. The client master key in SSL2 could be oversized and overrun a buffer. This vulnerability was also independently discovered by consultants at Neohapsis (http://www.neohapsis.com/) who have also demonstrated that the vulnerability is exploitable. Exploit code is NOT available at this time.

2. The session ID supplied to a client in SSL3 could be oversized and overrun a buffer.

3. The master key supplied to an SSL3 server could be oversized and overrun a stack-based buffer. This issues only affects OpenSSL 0.9.7 with Kerberos enabled.

4. Various buffers for ASCII representations of integers were too small on 64 bit platforms.

At the same time, various potential buffer overflows have had assertions added; these are not known to be exploitable.

Finally, a vulnerability was found by Adi Stav and James Yonan independently in the ASN1 parser which can be confused by supplying it with certain invalid encodings. There are no known exploits for this vulnerability.

All of these vulnerabilities are fixed in OpenSSL 0.9.6f. Patches have been applied to the versions of OpenSSL provided in this update to fix all of these problems, except for the ASN1 vulnerability, which a fix will be provided for once MandrakeSoft has had a chance to QA the new packages. In the meantime, it is is strongly encouraged that all users upgrade to these OpenSSL packages.

Update :

These new OpenSSL packages are available to additionally fix the ASN1 vulnerability described above. All Mandrake Linux users are encouraged to upgrade to these new packages.

The remote service seems to be using a version of OpenSSL that is older than 0.9.6e or 0.9.7-beta3.

Such versions are affected by a buffer overflow that may allow an attacker to execute arbitrary commands on the remote host with the privileges of the application itself.

ID	Name	Product	Family	Severity
17752	OpenSSL < 0.9.7-beta3 Buffer Overflow	Nessus	Web Servers	high
14973	Debian DSA-136-1 : openssl - multiple remote exploits	Nessus	Debian Local Security Checks	high
13949	Mandrake Linux Security Advisory : openssl (MDKSA-2002:046-1)	Nessus	Mandriva Local Security Checks	high
11060	OpenSSL < 0.9.6e / 0.9.7b3 Multiple Remote Vulnerabilities	Nessus	Gain a shell remotely	critical

Detections

Analytics

CVE-2002-0657

critical

Tenable Plugins

high

high

high

critical