OpenSSL up to 0.9.8/1.0.0q/1.0.1l/1.0.2 SSLv2 s2_srvr.c get_client_master_key CLIENT-MASTER-KEY CLEAR-KEY-LENGTH information disclosure

CVSS Meta Temp Score
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5.5$0-$5k0.00

A vulnerability, which was classified as critical, was found in OpenSSL up to 0.9.8/1.0.0q/1.0.1l/1.0.2 (Network Encryption Software). Affected is the function get_client_master_key of the file s2_srvr.c of the component SSLv2 Handler. The manipulation of the argument CLIENT-MASTER-KEY CLEAR-KEY-LENGTH with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The get_client_master_key function in s2_srvr.c in the SSLv2 implementation in OpenSSL before 0.9.8zf, 1.0.0 before 1.0.0r, 1.0.1 before 1.0.1m, and 1.0.2 before 1.0.2a accepts a nonzero CLIENT-MASTER-KEY CLEAR-KEY-LENGTH value for an arbitrary cipher, which allows man-in-the-middle attackers to determine the MASTER-KEY value and decrypt TLS ciphertext data by leveraging a Bleichenbacher RSA padding oracle, a related issue to CVE-2016-0800.

The weakness was presented 03/02/2016 by Alex with University of Michigan (Website). The advisory is available at git.openssl.org. This vulnerability is traded as CVE-2016-0703 since 12/16/2015. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1592 by the MITRE ATT&CK project.

The vulnerability scanner Nessus provides a plugin with the ID 82783 (CentOS 5 : openssl (CESA-2015:0800) (FREAK)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CentOS Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 350021 (Amazon Linux Security Advisory for openssl098e: ALAS-2016-682).

Upgrading to version 0.9.8zf, 1.0.0r, 1.0.1m or 1.0.2a eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at X-Force (111145) and Tenable (82783). See 68520, 74747, 81112 and 81139 for similar entries.

Productinfo

Type

Name

Version

License

Support

  • end of life (old version)

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.9
VulDB Temp Score: 5.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
ATT&CK: T1592

Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 82783
Nessus Name: CentOS 5 : openssl (CESA-2015:0800) (FREAK)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 14611
OpenVAS Name: Amazon Linux Local Check: alas-2016-682
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: OpenSSL 0.9.8zf/1.0.0r/1.0.1m/1.0.2a
Patch: ae50d8270026edf5b3c7f8aaa0c6677462b33d97

Timelineinfo

04/14/2015 🔍
04/15/2015 +1 days 🔍
12/16/2015 +245 days 🔍
02/29/2016 +75 days 🔍
03/01/2016 +1 days 🔍
03/02/2016 +0 days 🔍
03/02/2016 +0 days 🔍
03/03/2016 +1 days 🔍
03/05/2016 +2 days 🔍
07/08/2022 +2315 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: RHSA-2015:0800
Researcher: Alex
Organization: University of Michigan
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-0703 (🔍)
OVAL: 🔍

X-Force: 111145 - OpenSSL s2_srvr.c security bypass
SecurityTracker: 1035133
Vulnerability Center: 56994 - OpenSSL Remote Session Key Recovery in SSLv2 - CVE-2016-0703, Medium
SecurityFocus: 83743 - OpenSSL CVE-2016-0703 Information Disclosure Vulnerability

See also: 🔍

Entryinfo

Created: 03/03/2016 10:19
Updated: 07/08/2022 19:19
Changes: 03/03/2016 10:19 (70), 09/01/2018 08:38 (25), 07/08/2022 19:12 (6), 07/08/2022 19:19 (1)
Complete: 🔍

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