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CVE-2021-4050

CVE-2021-4050: Cross site scripting in remdex/livehelperchat

6.1

CVSS Score
3.0

Basic Information

CVE ID
CVE-2021-4050
GHSA ID
GHSA-97cc-825c-399g
EPSS Score
0.54761%
CWE
CWE-79
Published
12/10/2021
Updated
2/1/2023
KEV Status
No
Technology
TechnologyPHP

Technical Details

CVSS Vector
CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
Package NameEcosystemVulnerable VersionsFirst Patched Version
remdex/livehelperchatcomposer<= 2.0

Vulnerability Intelligence
Miggo AIMiggo AI

Miggo AIRoot Cause Analysis

The vulnerability stems from improper sanitization of user-uploaded SVG files. The commit 0ce1dd2 introduced SVG sanitization using enshrined/svg-sanitize, indicating these functions previously lacked proper input neutralization. Both handle_file_upload methods process file uploads and set file extensions but originally didn't sanitize SVG content. Attackers could upload malicious SVGs containing script tags that would execute when rendered, leading to stored XSS. The patch adds cleanSVG() calls to these workflows, confirming these were the vulnerable points.

Vulnerable functions

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

WAF Protection Rules

WAF Rule

liv***lp*r***t is vuln*r**l* to Improp*r N*utr*liz*tion o* Input *urin* W** P*** **n*r*tion ('*ross-sit* S*riptin*')

Reasoning

T** vuln*r**ility st*ms *rom improp*r s*nitiz*tion o* us*r-uplo**** SV* *il*s. T** *ommit ******* intro*u*** SV* s*nitiz*tion usin* *ns*rin**/sv*-s*nitiz*, in*i**tin* t**s* *un*tions pr*viously l**k** prop*r input n*utr*liz*tion. *ot* **n*l*_*il*_upl