VDB-133153 · CVE-2019-9844 · Qualys 277806

Khan Academy simple-markdown up to 0.4.3 URI 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

A vulnerability was found in Khan Academy simple-markdown up to 0.4.3. It has been declared as problematic. Affected by this vulnerability is some unknown processing of the component URI Handler. The manipulation with an unknown input 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. The summary by CVE is:

simple-markdown.js in Khan Academy simple-markdown before 0.4.4 allows XSS via a data: or vbscript: URI.

The bug was discovered 03/14/2019. The weakness was presented 04/09/2019 (Website). The advisory is shared at lists.fedoraproject.org. This vulnerability is known as CVE-2019-9844 since 03/15/2019. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

The vulnerability was handled as a non-public zero-day exploit for at least 26 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 277806 (Fedora Security Update for nodejs-simple-markdown (FEDORA-2019-8e7c71f45b)).

Upgrading to version 0.4.4 eliminates this vulnerability.

See VDB-210648, VDB-215638, VDB-215639 and VDB-216863 for similar entries.

Productinfo

Vendor

Khan Academy

Name

simple-markdown

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-74 / CWE-707
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: simple-markdown 0.4.4
Patch: github.com

Timelineinfo

03/14/2019 🔍
03/15/2019 +1 days 🔍
04/09/2019 +25 days 🔍
04/09/2019 +0 days 🔍
08/27/2023 +1601 days 🔍

Sourcesinfo

Advisory: FEDORA-2019-36ce1cb623
Status: Not defined

CVE: CVE-2019-9844 (🔍)
See also: 🔍

Entryinfo

Created: 04/09/2019 09:34 AM
Updated: 08/27/2023 03:00 PM
Changes: 04/09/2019 09:34 AM (59), 05/27/2020 04:26 PM (1), 08/27/2023 03:00 PM (5)
Complete: 🔍
Cache ID: 98:118:40