Local code execution via missing TextShaping.dll load
Published Dec 19, 2025 · Updated Dec 19, 2025
DLL hijacking in FileZilla Client 3.63.1 allows local users to execute code by planting TextShaping.dll in its application directory. On launch, the Windows client searches its application directory for the absent library and loads an attacker-supplied file without validating its origin. An attacker must already be able to write into that directory; the planted DLL then runs with the privileges of the user who starts the client.
Summary
What happened
DLL hijacking in FileZilla Client 3.63.1 allows local users to execute code by planting TextShaping.dll in its application directory. On launch, the Windows client searches its application directory for the absent library and loads an attacker-supplied file without validating its origin. An attacker must already be able to write into that directory; the planted DLL then runs with the privileges of the user who starts the client.
The record
- CVE
- CVE-2023-53959
- Published
- Dec 19, 2025
- Updated
- Dec 19, 2025
- Vendor
- FileZilla Project
- Product
- FileZilla Client
- Classifications
- CWE-427, T1574.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 19, 2025CVE publishedPublication date reported by the CVE source.
- Dec 19, 2025Record 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=3.63.1
What conditions does exploitation require?
What is affected?
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
- TextShaping.dll hijacking exploitfunctional · validated
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Technologies
Your stack
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Your stack
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