CVE-2012-5340Public exploit

Memory corruption via overflowing PDF object numbers

Published Jan 23, 2020 · Updated Sep 13, 2024

Integer overflow in MuPDF's PDF parser allows remote attackers to corrupt memory via crafted PDFs in MuPDF 1.0 and SumatraPDF 2.1.1. In pdf_lex.c, lex_number() accumulates decimal digits into an int without an overflow check, allowing an oversized ObjStm object number to become negative and index xref->table before its bounds check. A user must open the malicious document; the demonstrated out-of-bounds write produces an exploitable user-mode access violation.

CVSS severity7.8
High
EPSS probability5.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in MuPDF's PDF parser allows remote attackers to corrupt memory via crafted PDFs in MuPDF 1.0 and SumatraPDF 2.1.1. In pdf_lex.c, lex_number() accumulates decimal digits into an int without an overflow check, allowing an oversized ObjStm object number to become negative and index xref->table before its bounds check. A user must open the malicious document; the demonstrated out-of-bounds write produces an exploitable user-mode access violation.

The record

CVE
CVE-2012-5340
Published
Jan 23, 2020
Updated
Sep 13, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-190, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 13, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1203Exploitation for Client Execution

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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