OpenSSL 1.1.0a Message use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.2$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in OpenSSL 1.1.0a. Affected by this issue is some unknown functionality of the component Message Handler. The manipulation leads to use after free. This vulnerability is traded as CVE-2016-6309. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSL 1.1.0a (Network Encryption Software). It has been rated as critical. This issue affects an unknown code of the component Message Handler. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote attackers to cause a denial of service (use-after-free) or possibly execute arbitrary code via a crafted TLS session.

The bug was discovered 09/26/2016. The weakness was shared 09/26/2016 by Robert Swiecki with Google Security Team as 20160926.txt as confirmed advisory (Website). It is possible to read the advisory at openssl.org. The vendor cooperated in the coordination of the public release. The identification of this vulnerability is CVE-2016-6309 since 07/26/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are unknown but an exploit is available. The advisory points out:

The patch applied to address CVE-2016-6307 resulted in an issue where if a message larger than approx 16k is received then the underlying buffer to store the incoming message is reallocated and moved. Unfortunately a dangling pointer to the old location is left which results in an attempt to write to the previously freed location. This is likely to result in a crash, however it could potentially lead to execution of arbitrary code.

It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 4 days. During that time the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 93730 (FreeBSD : OpenSSL -- multiple vulnerabilities (91a337d8-83ed-11e6-bf52-b499baebfeaf)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD 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)).

Upgrading to version 1.1.0b eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (93730) and SecurityFocus (BID 93177†). The entries VDB-87879, VDB-88080, VDB-90396 and VDB-90937 are related to this item. Be aware that VulDB is the high quality source for 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: 8.5
VulDB Meta Temp Score: 8.2

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
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: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 93730
Nessus Name: FreeBSD : OpenSSL -- multiple vulnerabilities (91a337d8-83ed-11e6-bf52-b499baebfeaf)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 860965
OpenVAS Name: OpenSSL Use-After-Free Fix vulnerability (Linux)
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 1.1.0b
Patch: acacbfa7565c78d2273c0b2a2e5e803f44afefeb

Timelineinfo

07/26/2016 🔍
09/22/2016 +58 days 🔍
09/26/2016 +4 days 🔍
09/26/2016 +0 days 🔍
09/26/2016 +0 days 🔍
09/26/2016 +0 days 🔍
09/26/2016 +0 days 🔍
09/26/2016 +0 days 🔍
09/27/2016 +1 days 🔍
09/21/2022 +2185 days 🔍

Sourcesinfo

Product: openssl.org

Advisory: 20160926.txt
Researcher: Robert Swiecki
Organization: Google Security Team
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-6309 (🔍)
GCVE (CVE): GCVE-0-2016-6309
GCVE (VulDB): GCVE-100-92159

OVAL: 🔍

SecurityFocus: 93177 - OpenSSL CVE-2016-6309 Remote Code Execution Vulnerability
SecurityTracker: 1036885

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

Entryinfo

Created: 09/26/2016 17:36
Updated: 09/21/2022 11:09
Changes: 09/26/2016 17:36 (87), 07/07/2019 17:04 (6), 09/21/2022 11:09 (5)
Complete: 🔍
Cache ID: 216:02D:103

Be aware that VulDB is the high quality source for vulnerability data.

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