CVE-2021-43691Network attack vector

Unauthorized file copy via unvalidated font paths

Published Nov 29, 2021 · Updated Aug 4, 2024

Path traversal in Tripexpress 1.1 allows attackers to copy selected files into the dompdf font directory through command-line arguments. The load_font.php script passes $_SERVER["argv"] to install_font_family(), which copies each supplied font path without restricting its source location. Execution of the helper with crafted arguments is required; the demonstrated consequence is an unauthorized file copy, not broader code execution.

CVSS severity9.8
Critical
EPSS probability1.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Tripexpress 1.1 allows attackers to copy selected files into the dompdf font directory through command-line arguments. The load_font.php script passes $_SERVER["argv"] to install_font_family(), which copies each supplied font path without restricting its source location. Execution of the helper with crafted arguments is required; the demonstrated consequence is an unauthorized file copy, not broader code execution.

The record

CVE
CVE-2021-43691
Published
Nov 29, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-22
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 29, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS: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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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