OpenSSL 1.0.1s/1.0.2g AES-NI CBC MAC Check e_aes_cbc_hmac_sha1.c cryptographic issue

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

Summaryinfo

A vulnerability marked as critical has been reported in OpenSSL 1.0.1s/1.0.2g. The impacted element is an unknown function of the file crypto/evp/e_aes_cbc_hmac_sha1.c of the component AES-NI CBC MAC Check. The manipulation leads to cryptographic issue. This vulnerability is referenced as CVE-2016-2107. Remote exploitation of the attack is possible. Furthermore, an exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSL 1.0.1s/1.0.2g (Network Encryption Software) and classified as critical. This issue affects an unknown code of the file crypto/evp/e_aes_cbc_hmac_sha1.c of the component AES-NI CBC MAC Check. The manipulation with an unknown input leads to a cryptographic issue vulnerability. Using CWE to declare the problem leads to CWE-310. Impacted is confidentiality, integrity, and availability.

The weakness was published 05/03/2016 by Juraj Somorovsky with Oracle as 20160503.txt as confirmed advisory (Website). It is possible to read the advisory at openssl.org. The public release has been coordinated with the project team. The advisory contains:

This issue was introduced as part of the fix for Lucky 13 padding attack (CVE-2013-0169). The padding check was rewritten to be in constant time by making sure that always the same bytes are read and compared against either the MAC or padding bytes. But it no longer checked that there was enough data to have both the MAC and padding bytes.
The identification of this vulnerability is CVE-2016-2107 since 01/29/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. The attack technique deployed by this issue is T1600 according to MITRE ATT&CK. The advisory points out:
A MITM attacker can use a padding oracle attack to decrypt traffic when the connection uses an AES CBC cipher and the server support AES-NI.

A public exploit has been developed by Juraj Somorovsky and been published 1 days after the advisory. The exploit is available at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 20 days. During that time the estimated underground price was around $5k-$25k. 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)).

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:

ret &= constant_time_ge(maxpad, pad);

The vulnerability is also documented in the databases at Exploit-DB (39768), Tenable (91033) and SecurityFocus (BID 91787†). tools.cisco.com is providing further details. Similar entries are available at VDB-76354, VDB-78584, VDB-78603 and VDB-78601. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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License

Support

  • end of life (old version)

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.4

VulDB Base Score: 9.8
VulDB Temp Score: 8.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
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Exploitinginfo

Class: Cryptographic issue
CWE: CWE-310
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Juraj Somorovsky
Download: 🔍

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: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: OpenSSL 1.0.1t/1.0.2h
Patch: 68595c0c2886e7942a14f98c17a55a88afb6c292

Timelineinfo

01/29/2016 🔍
04/13/2016 +75 days 🔍
05/03/2016 +20 days 🔍
05/03/2016 +0 days 🔍
05/04/2016 +1 days 🔍
05/04/2016 +0 days 🔍
05/04/2016 +0 days 🔍
05/04/2016 +0 days 🔍
05/11/2016 +7 days 🔍
07/15/2016 +65 days 🔍
12/28/2024 +3088 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: 20160503.txt
Researcher: Juraj Somorovsky
Organization: Oracle
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-2107 (🔍)
GCVE (CVE): GCVE-0-2016-2107
GCVE (VulDB): GCVE-100-83255

OVAL: 🔍

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

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

Entryinfo

Created: 05/04/2016 11:25
Updated: 12/28/2024 10:54
Changes: 05/04/2016 11:25 (74), 11/12/2018 08:31 (27), 07/28/2022 07:50 (6), 12/28/2024 10:54 (14)
Complete: 🔍
Cache ID: 216::103

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