CVE-2014-4978 in rawstudio
Summary
by MITRE
The rs_filter_graph function in librawstudio/rs-filter.c in rawstudio might allow local users to truncate arbitrary files via a symlink attack on (1) /tmp/rs-filter-graph.png or (2) /tmp/rs-filter-graph.
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Analysis
by VulDB Data Team • 01/19/2023
The vulnerability identified as CVE-2014-4978 resides within the rawstudio image processing application, specifically in the rs_filter_graph function located in librawstudio/rs-filter.c. This flaw represents a classic symlink attack vulnerability that enables local attackers to manipulate file operations through carefully crafted symbolic links. The vulnerability manifests when the application creates temporary files in the /tmp directory without proper security checks, making it susceptible to race conditions and file manipulation attacks.
The technical implementation of this vulnerability involves the application's handling of temporary files during image filtering operations. When rawstudio processes images through its filtering capabilities, it generates temporary files named rs-filter-graph.png and rs-filter-graph in the /tmp directory. The flaw occurs because the application does not validate whether these temporary files are legitimate or if they have been replaced by symbolic links created by an attacker. This creates a window where an attacker can establish symbolic links with the same names before the application attempts to write to them, effectively redirecting the write operations to arbitrary locations on the filesystem.
From an operational perspective, this vulnerability allows local users to potentially overwrite or truncate any file that the rawstudio process has write permissions to, depending on the system's user context. The impact extends beyond simple file corruption as attackers could leverage this to overwrite critical system files, configuration data, or even executable programs. The vulnerability is particularly concerning because it operates at the file system level and can be exploited without requiring special privileges beyond local access. The attack vector is straightforward and reliable, making it a significant concern for any system where rawstudio is installed and used by multiple users.
The vulnerability aligns with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) race conditions, and demonstrates poor file handling practices that violate fundamental security principles. From an ATT&CK framework perspective, this represents a privilege escalation technique through file system manipulation, potentially falling under the T1068 privilege escalation tactics. The vulnerability also relates to T1499, which covers data destruction and tampering through file system operations. The exploitation requires minimal sophistication and can be automated, making it particularly dangerous in multi-user environments or systems where rawstudio is commonly used for image processing tasks.
Mitigation strategies should focus on implementing proper temporary file handling mechanisms that avoid predictable file names and use secure file creation patterns such as creating files with exclusive access permissions. The application should employ atomic file operations and validate file paths to prevent symlink attacks. System administrators should ensure that the /tmp directory has appropriate permissions and consider using secure temporary file creation functions that prevent symbolic link attacks. Additionally, the application should be updated to use more secure temporary file management practices that eliminate the race condition window entirely, ensuring that file creation operations are atomic and cannot be manipulated by attackers through symbolic link substitution.