CVE-2025-43903

Signature forgery via skipped PKCS7 SHA1 verification

Published Apr 18, 2025 · Updated Apr 21, 2025

Improper signature verification in freedesktop.org Poppler before 25.04.0 allows local users to forge PDF document signatures. NSSCryptoSignBackend.cc skips cryptographic verification for adbe.pkcs7.sha1 signatures and treats attacker-controlled signature data as valid. The NSS backend must process a PDF using this signature subfilter, leading consumers to place false trust in document integrity or signer authenticity.

CVSS severity3.3
Low
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper signature verification in freedesktop.org Poppler before 25.04.0 allows local users to forge PDF document signatures. NSSCryptoSignBackend.cc skips cryptographic verification for adbe.pkcs7.sha1 signatures and treats attacker-controlled signature data as valid. The NSS backend must process a PDF using this signature subfilter, leading consumers to place false trust in document integrity or signer authenticity.

The record

CVE
CVE-2025-43903
Published
Apr 18, 2025
Updated
Apr 21, 2025
Vendor
Libslirp Project
Product
Poppler
Classifications
CWE-347, T1553
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 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=0 <25.04.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Libslirp Project · Popplerversion=0 <25.04.0

Published CVSS scores

4.3MITRECVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
3.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1553Subvert Trust Controls

Public exploit references

No public exploit references are available in this record.

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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