CyberSecBulletin
CVE-2022-26649NVD status: Modified

SCALANCE X200-4P IRT: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2022-26649 is a high-severity buffer copy without checking size of input vulnerability in SCALANCE X200-4P IRT from Siemens, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SCALANCE X200-4P IRT versions: All versions < V5.5.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.4% chance of exploitation within 30 days, higher than 73% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Scalance X204-2 Firmware to 5.2.6 or a later version.
  2. Update Scalance X204-2fm Firmware to 5.2.6 or a later version.
  3. Update Scalance X204-2ld Firmware to 5.2.6 or a later version.
  4. Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
SiemensSCALANCE X200-4P IRTAll versions < V5.5.2Not stated
SiemensSCALANCE X201-3P IRTAll versions < V5.5.2Not stated
SiemensSCALANCE X201-3P IRT PROAll versions < V5.5.2Not stated
SiemensSCALANCE X202-2IRTAll versions < V5.5.2Not stated
SiemensSCALANCE X202-2P IRTAll versions < V5.5.2Not stated
SiemensSCALANCE X202-2P IRT PROAll versions < V5.5.2Not stated
SiemensSCALANCE X204-2All versions < V5.2.6Not stated
SiemensSCALANCE X204-2FMAll versions < V5.2.6Not stated
SiemensSCALANCE X204-2LDAll versions < V5.2.6Not stated
SiemensSCALANCE X204-2LD TSAll versions < V5.2.6Not stated
SiemensSCALANCE X204-2TSAll versions < V5.2.6Not stated
SiemensSCALANCE X204IRTAll versions < V5.5.2Not stated
SiemensSCALANCE X204IRT PROAll versions < V5.5.2Not stated
SiemensSCALANCE X206-1All versions < V5.2.6Not stated
SiemensSCALANCE X206-1LDAll versions < V5.2.6Not stated
SiemensSCALANCE X208All versions < V5.2.6Not stated
SiemensSCALANCE X208PROAll versions < V5.2.6Not stated
SiemensSCALANCE X212-2All versions < V5.2.6Not stated
SiemensSCALANCE X212-2LDAll versions < V5.2.6Not stated
SiemensSCALANCE X216All versions < V5.2.6Not stated
SiemensSCALANCE X224All versions < V5.2.6Not stated
SiemensSCALANCE XF201-3P IRTAll versions < V5.5.2Not stated
SiemensSCALANCE XF202-2P IRTAll versions < V5.5.2Not stated
SiemensSCALANCE XF204All versions < V5.2.6Not stated
SiemensSCALANCE XF204-2All versions < V5.2.6Not stated

Version data comes from the organisation that assigned the CVE; 33 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.6CriticalCNA (siemens.com)
CVSS 3.17.5HighNVD
CVSS 2.07.8HighNVD

Official description

A vulnerability has been identified in SCALANCE X200-4P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT (All versions < V5.5.2), SCALANCE X201-3P IRT PRO (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2IRT (All versions < V5.5.2), SCALANCE X202-2P IRT (All versions < V5.5.2), SCALANCE X202-2P IRT PRO (All versions < V5.5.2), SCALANCE X204-2 (All versions < V5.2.6), SCALANCE X204-2FM (All versions < V5.2.6), SCALANCE X204-2LD (All versions < V5.2.6), SCALANCE X204-2LD TS (All versions < V5.2.6), SCALANCE X204-2TS (All versions < V5.2.6), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT (All versions < V5.5.2), SCALANCE X204IRT PRO (All versions < V5.5.2), SCALANCE X206-1 (All versions < V5.2.6), SCALANCE X206-1LD (All versions < V5.2.6), SCALANCE X208 (All versions < V5.2.6), SCALANCE X208PRO (All versions < V5.2.6), SCALANCE X212-2 (All versions < V5.2.6), SCALANCE X212-2LD (All versions < V5.2.6), SCALANCE X216 (All versions < V5.2.6), SCALANCE X224 (All versions < V5.2.6), SCALANCE XF201-3P IRT (All versions < V5.5.2), SCALANCE XF202-2P IRT (All versions < V5.5.2), SCALANCE XF204 (All versions < V5.2.6), SCALANCE XF204-2 (All versions < V5.2.6), SCALANCE XF204-2BA IRT (All versions < V5.5.2), SCALANCE XF204IRT (All versions < V5.5.2), SCALANCE XF206-1 (All versions < V5.2.6), SCALANCE XF208 (All versions < V5.2.6). Affected devices do not properly validate the URI of incoming HTTP GET requests. This could allow an unauthenticated remote attacker to crash affected devices.

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

The underlying weakness: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in SCALANCE X200-4P IRT

All SCALANCE X200-4P IRT vulnerabilities

Recent Buffer Copy without Checking Size of Input vulnerabilities

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