CVE-2024-29384Public exploitNetwork attack vector

Sensitive-data disclosure via incomplete CSS rule sanitization

Published Apr 30, 2024 · Updated Aug 2, 2024

Information disclosure in CSS Exfil Protection 1.1.0 allows remote attackers to extract page data through crafted CSS rules. The content.js parseCSSRules logic skips URLs containing ;base64, anywhere and examines only unnested rules, so crafted URLs, CSS variables, and nested rules evade sanitization. The attack requires a page to process attacker-controlled CSS while the extension is enabled; successful requests disclose matched page-input fragments without modifying content or interrupting service.

CVSS severity7.5
High
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in CSS Exfil Protection 1.1.0 allows remote attackers to extract page data through crafted CSS rules. The content.js parseCSSRules logic skips URLs containing ;base64, anywhere and examines only unnested rules, so crafted URLs, CSS variables, and nested rules evade sanitization. The attack requires a page to process attacker-controlled CSS while the extension is enabled; successful requests disclose matched page-input fragments without modifying content or interrupting service.

The record

CVE
CVE-2024-29384
Published
Apr 30, 2024
Updated
Aug 2, 2024
Vendor
Mike Gualtieri
Product
CSS Exfil Protection
Classifications
CWE-200, T1048
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 30, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=- <=1.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mike Gualtieri · CSS Exfil Protectionversion=- <=1.1.0

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
T1048Exfiltration Over Alternative Protocol

Public exploit references

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

Technologies

Your stack

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Your stack

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