CVE-2025-53632 is a high-severity path traversal vulnerability (CWE-22) found in the ctfer-io chall-manager platform, a system designed to start Challenges on Demand for players. The vulnerability arises during the decoding of scenario files, specifically zip archives, where the software fails to properly validate the file paths before writing them to disk. This improper limitation allows an attacker to craft malicious zip files containing file paths that traverse directories outside the intended extraction folder, commonly known as a zip slip attack. Exploiting this flaw can lead to arbitrary file write operations anywhere on the filesystem accessible by the chall-manager process, potentially overwriting critical system or application files. Notably, exploitation does not require any authentication or authorization, meaning that any remote attacker with network access to the chall-manager service can trigger the vulnerability without user interaction. Although it is recommended to deploy chall-manager deep within a protected infrastructure to limit exposure, the inherent risk remains significant due to the lack of access controls. The vendor addressed this vulnerability in version 0.1.4 via a patch that properly validates and restricts file paths during archive extraction, mitigating the zip slip risk. The CVSS 4.0 base score is 8.8, reflecting the vulnerability's ease of exploitation (network vector, no privileges or user interaction required) and its high impact on confidentiality and integrity, though availability impact is moderate. No known exploits have been reported in the wild as of the publication date.

For European organizations using the ctfer-io chall-manager platform, this vulnerability poses a serious risk. Successful exploitation could allow attackers to overwrite or inject malicious files on critical systems, potentially leading to unauthorized code execution, data corruption, or system compromise. Given that chall-manager is used to manage challenge scenarios, likely in cybersecurity training, CTF events, or gamified security exercises, a compromised instance could undermine the integrity of these environments, disrupt training operations, or serve as a foothold for lateral movement within the network. The lack of authentication requirement increases the risk of external attackers exploiting exposed chall-manager instances, especially if deployed without adequate network segmentation. Organizations relying on this platform for security education or internal testing should be aware that an attacker could leverage this vulnerability to escalate privileges or implant persistent backdoors. Additionally, the potential for arbitrary file writes could impact confidentiality by exposing sensitive files or integrity by altering challenge content or system binaries. Availability impact is less direct but could occur if critical files are overwritten or deleted. Overall, the vulnerability could disrupt security operations and erode trust in training environments if not promptly addressed.

Organizations should immediately upgrade all instances of ctfer-io chall-manager to version 0.1.4 or later, which contains the patch fixing the path traversal vulnerability. Until upgrading is possible, it is critical to restrict network access to the chall-manager service by implementing strict firewall rules and network segmentation, ensuring it is not reachable from untrusted networks or the internet. Deploy chall-manager behind VPNs or within isolated environments to minimize exposure. Additionally, monitor logs for unusual file extraction activities or unexpected file writes that could indicate exploitation attempts. Employ file integrity monitoring on directories used by chall-manager to detect unauthorized changes. If feasible, run chall-manager with the least privileges necessary, using dedicated service accounts with restricted filesystem permissions to limit the impact of potential exploitation. Regularly audit and review deployment architectures to ensure that chall-manager is not directly exposed to untrusted users. Finally, incorporate this vulnerability into incident response plans and threat hunting activities to quickly identify and remediate any exploitation attempts.