Overview
The cybersecurity community has recently identified a severe vulnerability, designated as CVE-2025-54802, affecting pyLoad, the free and open-source download manager written in pure Python. This vulnerability can be exploited by potential attackers to compromise systems and leak data by enabling remote code execution (RCE). Particularly, pyLoad versions 0.5.0b3.dev89 and below are susceptible to this vulnerability, making it an urgent matter for users to update to the latest version or apply the necessary patches.
The severity of this vulnerability is underscored by its CVSS Severity Score, which is 9.8, indicating a critical level of risk. The vulnerability poses a significant threat as it allows unauthenticated attackers to write arbitrary files outside the designated storage directory, potentially leading to a system-wide compromise.
Vulnerability Summary
CVE ID: CVE-2025-54802
Severity: Critical (9.8 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Remote Code Execution, Privilege Escalation, Potential System Compromise, and Data Leakage
Affected Products
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Product | Affected Versions
pyLoad | 0.5.0b3.dev89 and below
How the Exploit Works
The vulnerability lies in the ‘addcrypted’ endpoint of pyload-ng. Here, an unsafe path construction vulnerability allows an attacker to exploit path traversal. By manipulating the ‘package’ parameter, an attacker can write arbitrary files outside the designated storage directory. This can be abused to overwrite critical system files, including cron jobs and systemd services, leading to privilege escalation and remote code execution as root.
Conceptual Example Code
Note that the following is a hypothetical example illustrating how an attacker might exploit the vulnerability:
POST /addcrypted HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "package": "../../../../etc/passwd" }In this example, the attacker is using a path traversal attack to overwrite the `/etc/passwd` file, a critical system file in Unix-based systems, potentially granting them unauthorized root access.
Mitigation Guidance
Users are advised to update to version 0.5.0b3.dev90 or later as this issue has been fixed in these versions. If updating is not immediately possible, consider implementing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. Regularly monitor your system logs for any suspicious activity and always maintain a strong, up-to-date backup of your critical data.