Code execution via APStartupCulture unsafe deserialization
Published Aug 2, 2021 · Updated Aug 3, 2024
Unsafe deserialization in CODESYS Development System 3.5.16 and 3.5.17 allows attackers to execute arbitrary commands via a crafted file. ComponentManager.StartupCultureSettings.method13 opens an extensionless APStartupCulture file from user or system profile storage and passes its contents directly to BinaryFormatter.Deserialize. The attacker must place the file in a searched local directory and induce the local user to start the application; successful exploitation runs code in that user's context.
Summary
What happened
Unsafe deserialization in CODESYS Development System 3.5.16 and 3.5.17 allows attackers to execute arbitrary commands via a crafted file. ComponentManager.StartupCultureSettings.method13 opens an extensionless APStartupCulture file from user or system profile storage and passes its contents directly to BinaryFormatter.Deserialize. The attacker must place the file in a searched local directory and induce the local user to start the application; successful exploitation runs code in that user's context.
The record
- CVE
- CVE-2021-21864
- Published
- Aug 2, 2021
- Updated
- Aug 3, 2024
- Vendor
- CODESYS GmbH
- Product
- CODESYS Development System V3
- Classifications
- CWE-502, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 2, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record 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.
- Affected versionversion=CODESYS GmbH CODESYS Development System 3.5.16, CODESYS GmbH CODESYS Development System 3.5.17
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Talos APStartupCulture deserialization proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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