CVE-2023-53942VulnerabilityPublished 18 Dec 2025

CVE-2023-53942: leefish File Thingie · Unrestricted File Upload

Affects leefish File ThingieSource CVE Database V5

Not known to be exploited · CVSS 9.4 Critical.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

9.4Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: High
Subsequent system confidentiality: High
Subsequent system integrity: High
Subsequent system availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: High: There is a total loss of confidentiality, resulting in all resources within the Subsequent System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Subsequent system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the Subsequent System. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the Subsequent System.
Subsequent system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Subsequent System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Subsequent System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubleefish/filethingie`pkg:github/leefish/filethingie`Other threats	Affected =2.5.7	Fixed in–

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AI-suggested

1. Upgrade File Thingie to a version that addresses this vulnerability as soon as a patch is released by the vendor. 2. If an immediate patch is unavailable, disable file upload functionality or restrict it to trusted users only. 3. Implement strict server-side validation to restrict allowed file types, explicitly blocking PHP and archive files that can contain executable scripts. 4. Use web application firewalls (WAFs) to detect and block suspicious file uploads and command injection attempts. 5. Monitor server logs for unusual file upload activity and execution of PHP scripts from upload directories. 6. Enforce the principle of least privilege for user accounts to limit the impact of compromised credentials. 7. Isolate the file upload directory from the web root or configure the web server to prevent execution of uploaded files. 8. Conduct regular security audits and penetration testing focusing on file upload functionalities. 9. Educate users about credential security to reduce the risk of account compromise. 10. Employ intrusion detection systems (IDS) to alert on anomalous system command executions.

Description

CVE-2023-53942 is a critical authenticated file upload vulnerability in File Thingie version 2.5.7 that allows attackers with limited privileges to upload malicious PHP zip archives. By uploading and extracting a crafted PHP payload, attackers can execute arbitrary system commands on the affected web server without user interaction. This vulnerability has a CVSS 4.0 score of 9.4, indicating a critical severity level due to its high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the ease of exploitation and potential for full system compromise make this a significant threat. European organizations using File Thingie 2.5.

Impact

For European organizations, this vulnerability poses a significant risk, especially for those using File Thingie 2.5.7 to manage sensitive or critical data. Successful exploitation could lead to unauthorized access to confidential information, data tampering, and potential service outages. The ability to execute arbitrary system commands could allow attackers to pivot within networks, deploy ransomware, or establish persistent backdoors. This is particularly concerning for sectors such as finance, healthcare, government, and critical infrastructure where data integrity and availability are paramount. The vulnerability’s requirement for authentication means insider threats or compromised credentials could be leveraged to exploit this flaw. Additionally, organizations with web-facing File Thingie instances increase their exposure to remote exploitation attempts. The lack of known exploits in the wild does not diminish the urgency, as the vulnerability’s characteristics make it a prime candidate for future exploitation campaigns targeting European entities.

Summary

CVE-2023-53942 is a critical vulnerability found in File Thingie version 2.5.7, a web-based file management application developed by leefish. The vulnerability arises from an authenticated file upload mechanism that does not properly restrict the types of files users can upload. Specifically, attackers with valid credentials can upload malicious PHP zip archives to the server. Once uploaded, these archives can be unzipped, allowing the embedded PHP scripts to be executed on the server. The malicious PHP payload can include commands that execute arbitrary system-level instructions, effectively allowing the attacker to gain control over the server environment. The vulnerability requires authentication but no additional user interaction, and the attack vector is network-based with low attack complexity. The CVSS 4.0 vector indicates no user interaction (UI:N), low attack complexity (AC:L), and privileges required are low (PR:L), meaning an attacker only needs limited access to exploit this flaw. The vulnerability impacts confidentiality, integrity, and availability severely, as attackers can exfiltrate data, modify or delete files, and disrupt services. No patches or known exploits are currently documented, but the critical nature of the flaw demands immediate attention from users of File Thingie 2.5.7.

References

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