OpenSSL 1.0.1s/1.0.2g Base64 Encoding crypto/evp/encode.c EVP_EncodeUpdate numeric error

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

Summaryinfo

A vulnerability described as critical has been identified in OpenSSL 1.0.1s/1.0.2g. This affects the function EVP_EncodeUpdate of the file crypto/evp/encode.c of the component Base64 Encoding. The manipulation results in numeric error. This vulnerability is identified as CVE-2016-2105. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in OpenSSL 1.0.1s/1.0.2g (Network Encryption Software). It has been classified as very critical. Affected is the function EVP_EncodeUpdate of the file crypto/evp/encode.c of the component Base64 Encoding. The manipulation with an unknown input leads to a numeric error vulnerability. CWE is classifying the issue as CWE-189. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Integer overflow in the EVP_EncodeUpdate function in crypto/evp/encode.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 binary data.

The weakness was released 05/03/2016 by Guido Vranken with Oracle as 20160503.txt as confirmed advisory (Website). The advisory is shared for download at openssl.org. The public release was coordinated with the vendor. This vulnerability is traded as CVE-2016-2105 since 01/29/2016. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/28/2022). The advisory points out:

An overflow can occur in the EVP_EncodeUpdate() function which is used for Base64 encoding of binary data. If an attacker is able to supply very large amounts of input data 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:

Internally to OpenSSL the EVP_EncodeUpdate() function is primarly used by the PEM_write_bio* family of functions. These are mainly used within the OpenSSL command line applications. These internal uses are not considered vulnerable because all calls are bounded with length checks so no overflow is possible. User applications that call these APIs directly with large amounts of untrusted data may be vulnerable.

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 (total > INT_MAX) {
   /* Too much output data! */
   *outl = 0;
   return;
}

The vulnerability is also documented in the databases at Tenable (91033) and SecurityFocus (BID 91787†). Further details are available at tools.cisco.com. Entries connected to this vulnerability are available at VDB-76354, VDB-78584, VDB-78603 and VDB-78601. VulDB is the best source for vulnerability data and more expert information about this specific topic.

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: 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: 5b814481f3573fa9677f3a31ee51322e2a22ee6a

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-2016-2105 (🔍)
GCVE (CVE): GCVE-0-2016-2105
GCVE (VulDB): GCVE-100-83256

OVAL: 🔍

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

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 05/04/2016 11:28
Updated: 07/28/2022 07:55
Changes: 05/04/2016 11:28 (81), 11/12/2018 08:31 (14), 07/28/2022 07:55 (6)
Complete: 🔍
Cache ID: 216:471:103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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