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CVE-2023-45871NVD status: Modified

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: Incorrect Calculation of Buffer Size

CVE-2023-45871 is a high-severity incorrect calculation of buffer size vulnerability in SIMATIC S7-1500 CPU 1518-4 PN/DP MFP from Siemens, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version V3.1.5 as the first without the flaw, so updating SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
  2. Update SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5 or a later version.
  3. Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1V1.1
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
LinuxLinux Kernel3.4 up to, but not including, 4.14.326; 4.15 up to, but not including, 4.19.295; 4.20 up to, but not including, 5.4.257; 5.5 up to, but not including, 5.10.195; 5.11 up to, but not including, 5.15.132; 5.16 up to, but not including, 6.1.53; 6.2 up to, but not including, 6.4.16; 6.5 up to, but not including, 6.5.34.14.326, 4.19.295, 5.4.257, 5.10.195, 5.15.132, 6.1.53
DebianDebian Linux10.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

An issue was discovered in drivers/net/ethernet/intel/igb/igb_main.c in the IGB driver in the Linux kernel before 6.5.3. A buffer size may not be adequate for frames larger than the MTU.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Calculation of Buffer Size

The product does not correctly calculate the size to be used when allocating a buffer.

How developers prevent this class of flaw

  • When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts & characters to & for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input buffer.
  • Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how the language handles numbers that are too large or too small for its underlying representation. Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
  • Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.

More Incorrect Calculation of Buffer Size vulnerabilities (CWE-131)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

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