OpenSSL crypto/bn/bn_print.c BN_bn2dec t out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenSSL. It has been rated as problematic. Affected by this vulnerability is the function BN_bn2dec of the file crypto/bn/bn_print.c. This manipulation of the argument t causes out-of-bounds write. This vulnerability is tracked as CVE-2016-2182. The attack is possible to be carried out remotely. No exploit exists. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as problematic was found in OpenSSL (Network Encryption Software) (version unknown). Affected by this vulnerability is the function BN_bn2dec of the file crypto/bn/bn_print.c. The manipulation of the argument t with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability.

The bug was discovered 08/25/2016. The weakness was disclosed 08/16/2016 by Shi Lei as USN-3087-1 as confirmed git commit (GIT Repository). The advisory is shared at git.openssl.org. The public release has been coordinated in cooperation with the project team. This vulnerability is known as CVE-2016-2182 since 01/29/2016. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. Responsible for the vulnerability is the following code: 

bn_data = OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));

The vulnerability scanner Nessus provides a plugin with the ID 95255 (AIX OpenSSL Advisory : openssl_advisory21.asc (SWEET32)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family AIX Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316384 (Cisco Unity Express OpenSSL Multiple Vulnerabilities (cisco-sa-20160927-openssl)).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.openssl.org. A possible mitigation has been published immediately after the disclosure of the vulnerability. The vulnerability will be addressed with the following lines of code:

bn_data_num = num / BN_DEC_NUM + 1;
bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG));
The git commit contains the following remark:
Fix by checking return value of BN_div_word() and checking writes don't overflow buffer.

The vulnerability is also documented in the databases at Tenable (95255), SecurityFocus (BID 92557†) and SecurityTracker (ID 1036688†). The entries VDB-87879, VDB-88080, VDB-90396 and VDB-90939 are pretty similar. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 95255
Nessus Name: AIX OpenSSL Advisory : openssl_advisory21.asc (SWEET32)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 59958
OpenVAS Name: RedHat Update for openssl RHSA-2016:1940-01
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Patch: 07bed46f332fce8c1d157689a2cdf915a982ae34

Timelineinfo

01/29/2016 🔍
08/16/2016 +200 days 🔍
08/16/2016 +0 days 🔍
08/16/2016 +0 days 🔍
08/25/2016 +9 days 🔍
08/25/2016 +0 days 🔍
08/25/2016 +0 days 🔍
09/16/2016 +22 days 🔍
11/22/2016 +67 days 🔍
09/14/2022 +2122 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: USN-3087-1
Researcher: Shi Lei
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-2182 (🔍)
GCVE (CVE): GCVE-0-2016-2182
GCVE (VulDB): GCVE-100-90937

OVAL: 🔍

SecurityFocus: 92557 - OpenSSL 'BN_bn2dec()' Function Out of Bounds Write Denial of Service Vulnerability
SecurityTracker: 1036688

See also: 🔍

Entryinfo

Created: 08/25/2016 11:29
Updated: 09/14/2022 09:56
Changes: 08/25/2016 11:29 (86), 07/07/2019 15:53 (7), 09/14/2022 09:56 (5)
Complete: 🔍
Cache ID: 216:128:103

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

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