VDB-111172 · CVE-2017-16876 · Nessus 105474

Mistune up to 0.8.0 mistune.py keyify key cross site scripting

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.
5.1	$0-$5k	0.00

Summaryinfo

A vulnerability described as problematic has been identified in Mistune up to 0.8.0. The affected element is the function keyify of the file mistune.py. Executing a manipulation of the argument key as part of Argument can lead to cross site scripting. This vulnerability is tracked as CVE-2017-16876. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Mistune up to 0.8.0 and classified as problematic. This vulnerability affects the function keyify of the file mistune.py. The manipulation of the argument key as part of a Argument leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

Cross-site scripting (XSS) vulnerability in the _keyify function in mistune.py in Mistune before 0.8.1 allows remote attackers to inject arbitrary web script or HTML by leveraging failure to escape the "key" argument.

The bug was discovered 11/17/2017. The weakness was disclosed 12/29/2017 (Website). The advisory is shared for download at lists.fedoraproject.org. This vulnerability was named CVE-2017-16876 since 11/17/2017. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

The vulnerability was handled as a non-public zero-day exploit for at least 40 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 105474 (Fedora 26 : python-mistune (2017-7b4149911a)), 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 l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 277140 (Fedora Security Update for python-mistune (FEDORA-2017-7b4149911a)).

Upgrading to version 0.8.1 eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (105474). The entry VDB-108284 is pretty similar. Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Mistune

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.2
VulDB Meta Temp Score: 5.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.1
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
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: 105474
Nessus Name: Fedora 26 : python-mistune (2017-7b4149911a)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 864466
OpenVAS Name: Fedora Update for python-mistune FEDORA-2017-7b4149911a
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Mistune 0.8.1
Patch: github.com

Timelineinfo

11/17/2017 🔍
11/17/2017 +0 days 🔍
12/27/2017 +40 days 🔍
12/28/2017 +1 days 🔍
12/29/2017 +1 days 🔍
12/29/2017 +0 days 🔍
12/30/2017 +1 days 🔍
01/19/2023 +1846 days 🔍