CVE-2017-9552 in Photo Station
Summary
by MITRE
A design flaw in authentication in Synology Photo Station 6.0-2528 through 6.7.1-3419 allows local users to obtain credentials via cmdline. Synology Photo Station employs the synophoto_dsm_user program to authenticate username and password by "synophoto_dsm_user --auth USERNAME PASSWORD", and local users are able to obtain credentials by sniffing "/proc/*/cmdline".
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Analysis
by VulDB Data Team • 10/17/2019
The vulnerability identified as CVE-2017-9552 represents a critical design flaw in the authentication mechanism of Synology Photo Station versions ranging from 6.0-2528 through 6.7.1-3419. This issue stems from the improper handling of command-line arguments during the authentication process, creating an exploitable weakness that allows local attackers to extract sensitive credential information. The authentication system relies on the synophoto_dsm_user program which executes with the command structure "synophoto_dsm_user --auth USERNAME PASSWORD" to validate user credentials. This design choice creates a significant security risk as the command-line arguments containing the username and password remain visible in the process tree, making them accessible to any local user with appropriate privileges.
The technical exploitation of this vulnerability occurs through the /proc filesystem interface, specifically by monitoring the cmdline entries of running processes. When the authentication command executes, the username and password parameters are passed directly as command-line arguments, which are then exposed in the /proc//cmdline files where represents the process identifier. This approach violates fundamental security principles by storing sensitive information in memory where it can be easily accessed by other processes running under the same user context. The cmdline interface in Linux systems provides a direct view into the command-line arguments passed to processes, making it a common target for credential harvesting attacks. This vulnerability aligns with CWE-255, which addresses insecure authentication mechanisms, and specifically demonstrates poor handling of sensitive data in memory.
The operational impact of this vulnerability extends beyond simple credential theft, as local users with basic system access can exploit this flaw to gain unauthorized access to user accounts within the Photo Station environment. Attackers can leverage this weakness to compromise multiple user accounts simultaneously, potentially leading to unauthorized data access, modification, or exfiltration from the photo storage system. The attack vector is particularly concerning because it requires minimal privileges to execute successfully, as local access is sufficient to monitor process cmdline information. This vulnerability effectively undermines the security model of the application by exposing authentication parameters through easily accessible system interfaces, creating a persistent threat that can be exploited by any local user or malicious process running on the same system.
Mitigation strategies for this vulnerability should focus on implementing secure credential handling practices that prevent sensitive information from being stored in command-line arguments. The most effective approach involves modifying the authentication mechanism to avoid passing credentials through command-line parameters entirely, instead utilizing secure input methods such as environment variables with restricted permissions or direct file-based input. Organizations should also implement process monitoring and alerting systems to detect unusual cmdline access patterns, particularly in environments where multiple users share the same system resources. Additionally, system administrators should consider implementing mandatory access controls and privilege separation to limit the scope of potential exploitation. This vulnerability demonstrates the importance of following security best practices outlined in the ATT&CK framework under credential access techniques, particularly those involving process injection and credential dumping methods that exploit insecure command-line argument handling. The remediation approach should include comprehensive system hardening measures and regular security audits to ensure that similar design flaws are not present in other applications within the system.