CVE-2024-21501Public exploitNetwork attack vector

File enumeration via PostCSS sourcemap oracle

Published Feb 24, 2024 · Updated Feb 13, 2025

Information exposure in ApostropheCMS sanitize-html before 2.12.1 allows remote attackers to enumerate server files via crafted HTML. When a backend permits the style attribute, the sanitizer passes its value to PostCSS with source-map processing enabled, so a crafted sourceMappingURL produces different sanitized output depending on whether the referenced path exists. The oracle reveals file and dependency names but not file contents, and configurations that reject style attributes are not exposed.

CVSS severity5.3
Medium
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Information exposure in ApostropheCMS sanitize-html before 2.12.1 allows remote attackers to enumerate server files via crafted HTML. When a backend permits the style attribute, the sanitizer passes its value to PostCSS with source-map processing enabled, so a crafted sourceMappingURL produces different sanitized output depending on whether the referenced path exists. The oracle reveals file and dependency names but not file contents, and configurations that reject style attributes are not exposed.

The record

CVE
CVE-2024-21501
Published
Feb 24, 2024
Updated
Feb 13, 2025
Vendor
ApostropheCMS
Product
sanitize-html
Classifications
CWE-200, CWE-538, T1083
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <*
  2. Affected versionversion=0 <2.12.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ApostropheCMS · sanitize-htmlversion=0 <*; version=0 <2.12.1

Published CVSS scores

5.3SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-538Insertion of Sensitive Information into Externally-Accessible File or Directory
T1083File and Directory Discovery

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo