CyberSecBulletin
CVE-2022-27579NVD status: Modified

SICK Flexi Soft Designer: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2022-27579 is a high-severity deserialization of untrusted data vulnerability in SICK Flexi Soft Designer, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected SICK Flexi Soft Designer versions: All versions up to and including 1.9.4 SP1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Flexi Soft Designer to 1.9.4 or a later version.
  2. Read the advisory on sick.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
SICK Flexi Soft DesignerSICK Flexi Soft DesignerAll versions up to and including 1.9.4 SP1Not stated
SickFlexi Soft Designerbefore 1.9.4; 1.9.41.9.4

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

A deserialization vulnerability in a .NET framework class used and not properly checked by Flexi Soft Designer in all versions up to and including 1.9.4 SP1 allows an attacker to craft malicious project files. Opening/importing such a malicious project file would execute arbitrary code with the privileges of the current user when opened or imported by the Flexi Soft Designer. This compromises confidentiality integrity and availability. For the attack to succeed a user must manually open a malicious project file.

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

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

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

References

Advisories

Recent Deserialization of Untrusted Data vulnerabilities

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