CVE-2023-53959
Filezilla-Project Filezilla Client 3.63.1
Raw vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2023-53959 is a high-severity Uncontrolled Search Path Element (CWE-427) vulnerability in Filezilla-Project Filezilla Client. Its CVSS base score is 8.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2023-53959 is a DLL hijacking vulnerability (CWE-427) in FileZilla Client version 3.63.1. The flaw occurs because the application attempts to load a missing TextShaping.dll from its directory, enabling attackers to place a malicious version of this DLL in the application directory to execute arbitrary code upon launch.
The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating it is exploitable remotely with low complexity, no privileges, and no user interaction. Attackers can generate a reverse shell payload using msfvenom, replace the missing DLL with it, and achieve remote code execution when a user launches the affected FileZilla Client.
Advisories and references, including those from Vulncheck (vulncheck.com/advisories/filezilla-client-dll-hijacking-via-missing-textshapingdll) and a proof-of-concept exploit on Exploit-DB (exploit-db.com/exploits/51267), detail the issue, while the FileZilla project site (filezilla-project.org) provides relevant updates for practitioners to review.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-204606
Vulnerability Data
FileZilla Client 3.63.1 contains a DLL hijacking vulnerability that allows attackers to execute malicious code by placing a crafted TextShaping.dll in the application directory. Attackers can generate a reverse shell payload using msfvenom and replace the missing DLL to achieve…
more
remote code execution when the application launches.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 2 hardening rules · 1 OS baseline
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Mitigating Controls (NIST 800-53 r5) AI
Establishes restrictive configuration settings that can define and lock down approved search paths.
Enforces approved authorizations so that only intended actors can place or modify elements in the search path.
Limits privileges so unintended actors cannot write to or control directories in the product's search path.
Restricts logical and physical access to change system configuration, including search-path settings and directories.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices directly address design of search paths and resource loading.
Hardened configuration baselines can enforce safe search-path settings and reduce exposure.
Execution allow-listing can block malicious binaries placed in hijackable search locations.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect uncontrolled search-path issues but does not prevent them by itself.
Restricting software installation reduces the chance that an attacker-controlled path element is introduced into the search path.
Secure system architecture and engineering principles require explicit control over search paths and resource locations.
Secure coding practices directly address the use of fixed or controlled search paths that can be influenced by unintended actors.
Configuration management can enforce approved search-path settings but does not inherently prevent the weakness.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-427