OpenSSL 1.0.1s/1.0.2g crypto/evp/evp_enc.c EVP_EncryptUpdate numeric error

CVSS Meta Temp Score
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8.5$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in OpenSSL 1.0.1s/1.0.2g. This impacts the function EVP_EncryptUpdate of the file crypto/evp/evp_enc.c. This manipulation causes numeric error. This vulnerability is tracked as CVE-2016-2106. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSL 1.0.1s/1.0.2g (Network Encryption Software). It has been declared as very critical. Affected by this vulnerability is the function EVP_EncryptUpdate of the file crypto/evp/evp_enc.c. The manipulation with an unknown input leads to a numeric error vulnerability. The CWE definition for the vulnerability is CWE-189. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Integer overflow in the EVP_EncryptUpdate function in crypto/evp/evp_enc.c in OpenSSL before 1.0.1t and 1.0.2 before 1.0.2h allows remote attackers to cause a denial of service (heap memory corruption) via a large amount of data.

The weakness was disclosed 05/03/2016 by Guido Vranken with Oracle as 20160503.txt as confirmed advisory (Website). The advisory is shared at openssl.org. The public release has been coordinated in cooperation with the project team. This vulnerability is known as CVE-2016-2106 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. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/28/2022). Responsible for the vulnerability is the following code: 

if (i + inl < bl) {
The advisory points out:
An overflow can occur in the EVP_EncryptUpdate() function. If an attacker is able to supply very large amounts of input data after a previous call to EVP_EncryptUpdate() with a partial block then a length check can overflow resulting in a heap corruption.

The vulnerability was handled as a non-public zero-day exploit for at least 61 days. During that time the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 91033 (RHEL 7 : openssl (RHSA-2016:0722)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Red Hat Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196457 (Ubuntu Security Notification for Openssl Vulnerabilities (USN-2959-1)). The advisory illustrates:

Following an analysis of all OpenSSL internal usage of the EVP_EncryptUpdate() function all usage is one of two forms. The first form is where the EVP_EncryptUpdate() call is known to be the first called function after an EVP_EncryptInit(), and therefore that specific call must be safe. The second form is where the length passed to EVP_EncryptUpdate() can be seen from the code to be some small value and therefore there is no possibility of an overflow. Since all instances are one of these two forms, it is believed that there can be no overflows in internal code due to this problem. It should be noted that EVP_DecryptUpdate() can call EVP_EncryptUpdate() in certain code paths. Also EVP_CipherUpdate() is a synonym for EVP_EncryptUpdate(). All instances of these calls have also been analysed too and it is believed there are no instances in internal usage where an overflow could occur.

Upgrading to version 1.0.1t or 1.0.2h eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The vulnerability will be addressed with the following lines of code:

if (bl - i > inl) {

The vulnerability is also documented in the databases at Tenable (91033) and SecurityFocus (BID 91787†). Additional details are provided at tools.cisco.com. The entries VDB-76354, VDB-78584, VDB-78603 and VDB-78601 are pretty similar. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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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: 8.7
VulDB Meta Temp Score: 8.5

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Numeric error
CWE: CWE-189
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: 91033
Nessus Name: RHEL 7 : openssl (RHSA-2016:0722)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 841567
OpenVAS Name: SuSE Update for openssl openSUSE-SU-2016:1240-1 (openssl)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: OpenSSL 1.0.1t/1.0.2h
Patch: 3f3582139fbb259a1c3cbb0a25236500a409bf26

Timelineinfo

01/29/2016 🔍
03/03/2016 +34 days 🔍
05/03/2016 +61 days 🔍
05/03/2016 +0 days 🔍
05/04/2016 +1 days 🔍
05/04/2016 +0 days 🔍
05/11/2016 +7 days 🔍
07/15/2016 +65 days 🔍
07/28/2022 +2204 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: 20160503.txt
Researcher: Guido Vranken
Organization: Oracle
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-2106 (🔍)
GCVE (CVE): GCVE-0-2016-2106
GCVE (VulDB): GCVE-100-83257

OVAL: 🔍

SecurityFocus: 91787 - Oracle July 2016 Critical Patch Update Multiple Vulnerabilities
SecurityTracker: 1035721

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 05/04/2016 11:31
Updated: 07/28/2022 08:00
Changes: 05/04/2016 11:31 (82), 11/12/2018 08:32 (14), 07/28/2022 08:00 (6)
Complete: 🔍
Cache ID: 216:F3E:103

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

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