CVE Tools

CVE-2021-21865

A unsafe deserialization vulnerability exists in the PackageManagement.plugin ExtensionMethods.Clone() functionality of CODESYS GmbH CODESYS Development System 3.5.16. A specially crafted file can ...

No known exploitation. EPSS puts it in the 69th percentile. A vendor fix is available.

Published Updated Sources: CVE.org, NVD, BDU, CSAF

What to do

The vendor has published a fix. Version details are below where the sources state them.

What it is

From the CVE record

Starting with Festo Automation Suite (FAS) version 2.8.0.138, the suite is delivered only with a connector to Codesys, rather than including Codesys directly. Prior to this version, Codesys was bundled within the FAS installation. From version 2.8.0.138 onwards, customers are required to download and install Codesys independently. This change impacts the handling of security vulnerabilities (CVEs) related to Codesys. Any Codesys-related security issues must now be addressed by the customer through their separate Codesys installation. The FAS itself includes only the connector component, which is maintained and updated within the suite. Please ensure that Codesys is kept up to date independently to mitigate any potential security risks associated with the Codesys software.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS69th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

1.3% chance of exploitation activity in the next 30 days, which ranks it in the 69th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

6 events over 1207 days, from the signal feeds we watch.

  1. Patch availableworkaround available, record updated
  2. Publishedweakness classified, att&ck mapped

Affected products

Technical detail

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Scored 7.8 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

Watch the software you run.

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We'll flag the next CVE, public exploit or patch for Schneider Electric, not every advisory.

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