Miggo Logo

CVE-2018-19057: SimpleMDE XSS Vulnerability

6.1

CVSS Score
3.0

Basic Information

EPSS Score
0.45059%
Published
11/21/2018
Updated
9/7/2023
KEV Status
No
Technology
TechnologyJavaScript

Technical Details

CVSS Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Package NameEcosystemVulnerable VersionsFirst Patched Version
simplemdenpm<= 1.11.2

Vulnerability Intelligence
Miggo AIMiggo AI

Miggo AIRoot Cause Analysis

The vulnerability description explicitly mentions XSS via IMG onerror attributes and A element mishandling. In Markdown editors, image and link rendering functions are typically responsible for converting markdown syntax to HTML elements. The functions inlineRenderer.image and inlineRenderer.link would directly handle these conversions. The lack of input sanitization in these specific functions would allow injection of malicious attributes (for images) and unsafe URL schemes (for links), matching the described attack vectors. The confidence is high as these are the primary functions responsible for the vulnerable HTML element construction mentioned in the advisory.

Vulnerable functions

Only Mi**o us*rs **n s** t*is s**tion

WAF Protection Rules

WAF Rule

Simpl*M** *.**.* **s XSS vi* *n on*rror *ttri*ut* o* * *r**t** IM* *l*m*nt, or vi* **rt*in input wit* `[` *n* `(` ***r**t*rs, w*i** is mis**n*l** *urin* *onstru*tion o* *n `*` *l*m*nt.

Reasoning

T** vuln*r**ility **s*ription *xpli*itly m*ntions XSS vi* IM* on*rror *ttri*ut*s *n* * *l*m*nt mis**n*lin*. In M*rk*own **itors, im*** *n* link r*n**rin* *un*tions *r* typi**lly r*sponsi*l* *or *onv*rtin* m*rk*own synt*x to *TML *l*m*nts. T** *un*tio