CVE-2024-45491Network attack vector

Memory corruption via unchecked DTD allocation multiplication

Published Aug 30, 2024 · Updated Jul 14, 2026

Integer overflow in Expat Project libexpat before 2.6.3 allows remote attackers to corrupt memory via crafted XML on 32-bit platforms. In xmlparse.c, dtdCopy multiplies oldE->nDefaultAtts by sizeof(DEFAULT_ATTRIBUTE) without checking whether the allocation size wraps, then passes the undersized result to the allocator. The flaw requires a platform where UINT_MAX equals SIZE_MAX; resulting heap corruption can crash the process or enable arbitrary code execution.

CVSS severity7.3
High
EPSS probability1.13%
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 Expat Project libexpat before 2.6.3 allows remote attackers to corrupt memory via crafted XML on 32-bit platforms. In xmlparse.c, dtdCopy multiplies oldE->nDefaultAtts by sizeof(DEFAULT_ATTRIBUTE) without checking whether the allocation size wraps, then passes the undersized result to the allocator. The flaw requires a platform where UINT_MAX equals SIZE_MAX; resulting heap corruption can crash the process or enable arbitrary code execution.

The record

CVE
CVE-2024-45491
Published
Aug 30, 2024
Updated
Jul 14, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 30, 2024CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 2026Record 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=V3.1.5 <*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*
Expat Project · libexpatversion=0 <2.6.3
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.5 <*
Siemens · SCALANCE XCM/XRM/XCH/XRH-300 familyversion=0 <V3.1
Siemens · RUGGEDCOM RST2428Pversion=0 <V3.1
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*

Published CVSS scores

7.3CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
7.3Siemens ProductCERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound

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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