OpenSSL up to 0.9.7b ASN.1 Parser denial of service

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenSSL. It has been classified as critical. The affected element is an unknown function of the component ASN.1 Parser. Performing a manipulation results in denial of service. This vulnerability is cataloged as CVE-2003-0851. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in OpenSSL (Network Encryption Software). This affects an unknown code block of the component ASN.1 Parser. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

OpenSSL 0.9.6k allows remote attackers to cause a denial of service (crash via large recursion) via malformed ASN.1 sequences.

The bug was discovered 11/04/2003. The weakness was shared 11/04/2003 by Mark J. Cox with OpenSSL (Website). The advisory is shared at openssl.org. This vulnerability is uniquely identified as CVE-2003-0851 since 10/10/2003. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are unknown but a public exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 1136 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 17749 (OpenSSL < 0.9.6l Denial of Service), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Web Servers and running in the context r.

Upgrading to version 0.9.6l eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at openssl.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published immediately after the disclosure of the vulnerability. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 3464.

The vulnerability is also documented in the databases at X-Force (13595), Tenable (17749), SecurityFocus (BID 8970†), OSVDB (2765†) and Secunia (SA17381†). Further details are available at ftp.openssl.org. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

Version

License

Support

  • end of life (old version)

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 6.7

VulDB Base Score: 7.5
VulDB Temp Score: 6.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 17749
Nessus Name: OpenSSL < 0.9.6l Denial of Service
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: OpenSSL 0.9.6l
Patch: openssl.org
TippingPoint: 🔍

Timelineinfo

09/24/2000 🔍
10/10/2003 +1111 days 🔍
11/04/2003 +25 days 🔍
11/04/2003 +0 days 🔍
11/04/2003 +0 days 🔍
11/04/2003 +0 days 🔍
11/04/2003 +0 days 🔍
11/04/2003 +0 days 🔍
11/06/2003 +1 days 🔍
12/01/2003 +25 days 🔍
07/14/2004 +226 days 🔍
11/01/2005 +475 days 🔍
01/04/2012 +2255 days 🔍
01/22/2025 +4767 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: openssl.org
Researcher: Mark J. Cox
Organization: OpenSSL
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2003-0851 (🔍)
GCVE (CVE): GCVE-0-2003-0851
GCVE (VulDB): GCVE-100-369

OVAL: 🔍

CERT: 🔍
X-Force: 13595 - OpenSSL ASN.1 sequence denial of service, Medium Risk
SecurityFocus: 8970 - OpenSSL ASN.1 Large Recursion Remote Denial Of Service Vulnerability
Secunia: 17381 - Fedora update for openssl096b, Moderately Critical
OSVDB: 2765 - OpenSSL ASN.1 Large Recursion DoS
Vulnerability Center: 4734 - [cisco-sa-20030930-ssl] DoS in OpenSSL via ASN.1 sequences, Medium

scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍

Entryinfo

Created: 11/06/2003 10:12
Updated: 01/22/2025 08:16
Changes: 11/06/2003 10:12 (95), 06/27/2019 09:00 (3), 01/22/2025 08:16 (19)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Are you interested in using VulDB?

Download the whitepaper to learn more about our service!