CVE-2024-45490Network attack vector

Memory corruption via unchecked negative buffer length

Published Aug 30, 2024 · Updated Jul 14, 2026

Memory corruption in Expat libexpat before 2.6.3 allows attackers to crash or execute code in applications that expose XML_ParseBuffer. XML_ParseBuffer accepts a negative length, and a later XML_GetBuffer call treats the invalid state as legitimate and corrupts process memory. Exploitation requires a consuming application to pass the negative length and then request another buffer; the resulting consequence is an application crash or code execution.

CVSS severity9.8
Critical
EPSS probability1.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Expat libexpat before 2.6.3 allows attackers to crash or execute code in applications that expose XML_ParseBuffer. XML_ParseBuffer accepts a negative length, and a later XML_GetBuffer call treats the invalid state as legitimate and corrupts process memory. Exploitation requires a consuming application to pass the negative length and then request another buffer; the resulting consequence is an application crash or code execution.

The record

CVE
CVE-2024-45490
Published
Aug 30, 2024
Updated
Jul 14, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-190, T1499.004
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

9.8CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8Siemens ProductCERTCVSS: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.

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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-190Integer Overflow or Wraparound
T1499.004Application or System Exploitation DoS

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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