CVE-2021-44737Known exploitationPublic exploitNetwork attack vector

Configuration overwrite via unchecked PJL file path

Published Jan 20, 2022 · Updated Aug 4, 2024

Path traversal in the PJL processor of affected Lexmark printer firmware allows remote attackers to overwrite internal configuration files. The proprietary LDLWELCOMESCREEN handler passes its FILE argument directly to open() without restricting traversal outside an intended directory. No authentication is required in the default configuration; writes are limited to nonexistent paths with existing writable parent directories and enable root code execution when chained with a process crash.

CVSS severity8.6
High
EPSS probability1.44%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in the PJL processor of affected Lexmark printer firmware allows remote attackers to overwrite internal configuration files. The proprietary LDLWELCOMESCREEN handler passes its FILE argument directly to open() without restricting traversal outside an intended directory. No authentication is required in the default configuration; writes are limited to nonexistent paths with existing writable parent directories and enable root code execution when chained with a process crash.

The record

CVE
CVE-2021-44737
Published
Jan 20, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-22, CAPEC-126, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 1, 2021Exploitation reportedPwn2Own 2021 successful exploitation
  2. Jan 20, 2022CVE publishedPublication date reported by the CVE source.
  3. 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

8.8Trend Micro Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.6LexmarkCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/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 exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CAPEC-126Path Traversal
T1190Exploit Public-Facing Application

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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