VulnerabilityPublished 10 Jun 2025

CVE-2025-5952: Zend.To · OS Command Injection

Affects Zend.ToSource CVE Database V5

Public exploit available · CVSS 6.9 Medium · fixed in 6.10 : patch Zend.To as a priority.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 1.6% chance of exploitation in 30 days – higher than 77% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.10

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

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 or the CVSS exploit maturity 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

AI-suggested

Immediate upgrade of Zend.To installations from version 6.10-6 Beta to at least version 6.10-7, or preferably to the latest stable release (6.15-8 or newer) which includes additional security enhancements.
Implement strict input validation and sanitization on all user-supplied parameters, especially those passed to system-level commands.
Restrict execution privileges of the web server process to the minimum necessary, employing the principle of least privilege to limit the impact of any command injection.
Employ web application firewalls (WAFs) with custom rules to detect and block suspicious command injection patterns targeting the file_1 parameter.
Monitor logs for unusual command execution attempts or anomalies in the NSSDropoff.php access patterns.
Conduct regular security assessments and penetration tests focusing on injection vulnerabilities in web applications.
Isolate Zend.To servers within segmented network zones to reduce lateral movement risk in case of compromise.
Educate administrators on timely patch management and vulnerability disclosure monitoring to ensure rapid response to emerging threats.

Description

A vulnerability, which was classified as critical, has been found in Zend.To up to 6.10-6 Beta. This issue affects the function exec of the file NSSDropoff.php. The manipulation of the argument file_1 leads to os command injection. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 6.10-7 is able to address this issue. It is recommended to upgrade the affected component. This affects a rather old version of the software. The vendor recommends updating to the latest release. Additional countermeasures have been added in 6.15-8.

Impact

For European organizations using Zend.To, especially those running the affected 6.10-6 Beta version, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized remote code execution, resulting in data breaches, service disruption, or lateral movement within the network. Organizations handling sensitive or regulated data (e.g., GDPR-protected personal data) could face compliance violations and reputational damage. The ability to execute OS commands remotely without authentication makes this vulnerability particularly dangerous for public-facing instances. The impact is heightened for sectors relying on secure file transfers such as government agencies, financial institutions, healthcare providers, and critical infrastructure operators. Additionally, compromised servers could be leveraged as pivot points for broader attacks or malware deployment. Although no active exploits are reported yet, the public availability of exploit details necessitates urgent remediation to prevent potential targeted attacks against European entities.

Summary

CVE-2025-5952 is a security vulnerability identified in Zend.To versions up to 6.10-6 Beta. The flaw resides in the NSSDropoff.php file, specifically in the exec function, where the argument file_1 can be manipulated by an attacker to perform OS command injection. This type of vulnerability allows an attacker to execute arbitrary operating system commands on the server hosting the vulnerable Zend.To instance. The vulnerability can be exploited remotely without requiring any authentication or user interaction, increasing the risk of widespread exploitation. The CVSS 4.0 base score is 6.9, categorized as medium severity, reflecting a network attack vector with low complexity and no privileges or user interaction needed. The impact on confidentiality, integrity, and availability is rated as low individually but combined can lead to significant compromise depending on the commands executed. The vulnerability affects an older beta version of Zend.To, a file transfer web application used for secure file sharing. The vendor has released version 6.10-7 to address this issue and further strengthened countermeasures in version 6.15-8. No known exploits are currently reported in the wild, but public disclosure of the exploit code increases the risk of future attacks. The vulnerability’s root cause is insufficient input validation and sanitization of the file_1 parameter before passing it to the exec function, enabling injection of malicious shell commands. This can lead to unauthorized command execution, potentially allowing attackers to gain control over the server, access sensitive data, or disrupt service availability.

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 11 Jul 2025, 00:47 UTC

Technical details

References

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