CVE-2023-23924Public exploitNetwork attack vector

Arbitrary URL access via case-sensitive SVG validation

Published Jan 31, 2023 · Updated Mar 10, 2025

URI validation bypass in dompdf before 2.0.2 allows remote attackers to invoke arbitrary protocols through crafted SVG input. In src/Image/Cache.php, a case-sensitive comparison ignores mixed-case Image elements, so their href values skip the protocol allowlist. The caller must accept attacker-controlled SVG; on PHP before 8.0.0, phar URLs trigger object deserialization and at least file deletion, with code execution dependent on available classes.

CVSS severity10.0
Critical
EPSS probability3.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

URI validation bypass in dompdf before 2.0.2 allows remote attackers to invoke arbitrary protocols through crafted SVG input. In src/Image/Cache.php, a case-sensitive comparison ignores mixed-case Image elements, so their href values skip the protocol allowlist. The caller must accept attacker-controlled SVG; on PHP before 8.0.0, phar URLs trigger object deserialization and at least file deletion, with code execution dependent on available classes.

The record

CVE
CVE-2023-23924
Published
Jan 31, 2023
Updated
Mar 10, 2025
Vendor
dompdf
Product
dompdf
Classifications
CWE-863, CWE-551, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2025Record 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=< 2.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

dompdf · dompdfversion=< 2.0.2

Published CVSS scores

10.0GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:H
9.8Canonical UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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-863Incorrect Authorization
CWE-551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
T1190Exploit Public-Facing Application

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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