CVE-2026-52101 in linux-server
Summary
by MITRE • 07/15/2026
An issue in andreimarcu linux-server v.1.0 through v.2.3.8 allows a remote attacker to obtain sensitive information via the function uploadRemote function in upload.go
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Analysis
by VulDB Data Team • 07/15/2026
The vulnerability resides within the andreimarcu linux-server software version 1.0 through 2.3.8 where a remote attacker can exploit the uploadRemote function in the upload.go file to gain access to sensitive information. This represents a critical security flaw that undermines the integrity and confidentiality of the system's data handling mechanisms. The uploadRemote function appears to lack proper input validation and sanitization measures, creating an avenue for malicious actors to manipulate the upload process and extract confidential data from the server environment. Such vulnerabilities typically arise when developers fail to implement robust security controls during the development lifecycle, particularly in functions that handle external data inputs.
The technical nature of this flaw aligns with common security weaknesses documented in the Common Weakness Enumeration catalog under CWE-20, which describes "Improper Input Validation" as a fundamental issue where software fails to properly validate or sanitize input data. The vulnerability manifests through the improper handling of remote file upload operations, where the system does not adequately verify the legitimacy of uploaded files or their contents. This weakness allows attackers to potentially inject malicious payloads or manipulate the upload process to access restricted system information. The function's design likely permits unrestricted file operations without proper authorization checks or data integrity verification mechanisms.
Operationally, this vulnerability poses significant risks to organizations relying on the affected linux-server software for their infrastructure services. Remote attackers can leverage this flaw to obtain sensitive information including but not limited to system credentials, configuration files, user data, and potentially system architecture details that could facilitate further attacks. The impact extends beyond simple information disclosure as it may enable privilege escalation or lateral movement within the network environment. According to the MITRE ATT&CK framework, this vulnerability maps to T1074 - Data Staged and T1566 - Phishing, as attackers can use the information obtained to craft more sophisticated attacks or establish persistent access to the compromised systems.
Mitigation strategies should focus on implementing comprehensive input validation controls within the uploadRemote function, including strict file type checking, size limitations, and content verification mechanisms. Organizations should immediately patch their installations to versions that address this vulnerability, while also implementing network segmentation and monitoring solutions to detect suspicious upload activities. The implementation of proper access controls, file permission settings, and regular security audits can significantly reduce the attack surface. Additionally, developers should follow secure coding practices as outlined in OWASP Top Ten and NIST Cybersecurity Framework guidelines to prevent similar vulnerabilities from emerging in future releases of the software.