VDB-99230 · CVE-2016-10211 · BID 98078

YARA 3.5.0 libyara/grammar.y yr_parser_lookup_loop_variable use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.

A vulnerability was found in YARA 3.5.0 and classified as problematic. Affected by this issue is the function yr_parser_lookup_loop_variable of the file libyara/grammar.y. 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 availability.

The bug was discovered 12/06/2016. The weakness was published 04/03/2017 (GitHub Repository). The advisory is available at github.com. This vulnerability is handled as CVE-2016-10211 since 02/07/2017. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 118 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 99743 (Fedora 25 : yara (2017-11ac1e31eb)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context local. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276651 (Fedora Security Update for yara (FEDORA-2017-11ac1e31eb)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 4 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (99743). Similar entries are available at 99229, 99244, 99245 and 100634.



CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.3
VulDB Temp Score: 4.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍



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

NVD Base Score: 🔍


Class: Use after free
CWE: CWE-416 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Nessus ID: 99743
Nessus Name: Fedora 25 : yara (2017-11ac1e31eb)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for yara FEDORA-2017-9941306740
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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


Recommended: Upgrade
Status: 🔍

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

Patch: github.com


12/06/2016 🔍
02/07/2017 +63 days 🔍
04/03/2017 +55 days 🔍
04/03/2017 +0 days 🔍
04/03/2017 +0 days 🔍
04/03/2017 +0 days 🔍
04/29/2017 +26 days 🔍
05/01/2017 +2 days 🔍
11/24/2022 +2033 days 🔍


Advisory: FEDORA-2017-11ac1e31eb
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-10211 (🔍)
SecurityFocus: 98078 - YARA CVE-2016-10211 Denial of Service Vulnerability
OSVDB: - CVE-2016-10211 - YARA - Use-After-Free Issue

See also: 🔍


Created: 04/03/2017 04:53 PM
Updated: 11/24/2022 04:50 PM
Changes: 04/03/2017 04:53 PM (81), 11/24/2022 04:43 PM (5), 11/24/2022 04:50 PM (1)
Complete: 🔍


No comments yet. Languages: en.

Please log in to comment.

Do you know our Splunk app?

Download it now for free!