CVE-2018-1797 in WebSphere Application Server
Summary
by MITRE
IBM WebSphere Application Server 7.0, 8.0, 8.5, and 9.0 using Enterprise bundle Archives (EBA) could allow a local attacker to traverse directories on the system. By persuading a victim to extract a specially-crafted ZIP archive containing "dot dot slash" sequences (../), an attacker could exploit this vulnerability to write to arbitrary files on the system. Note: This vulnerability is known as "Zip-Slip". IBM X-Force ID: 149427.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/06/2023
The vulnerability identified as CVE-2018-1797 represents a critical directory traversal flaw affecting IBM WebSphere Application Server versions 7.0, 8.0, 8.5, and 9.0 when processing Enterprise Bundle Archives. This issue manifests through the improper handling of archive extraction operations, specifically when the application encounters "dot dot slash" sequences in file paths within ZIP archives. The vulnerability is commonly referred to as "Zip-Slip" due to its exploitation mechanism involving directory traversal patterns that allow attackers to manipulate file paths beyond the intended extraction boundaries. The flaw exists within the archive processing logic that fails to properly sanitize or validate file paths during decompression operations, creating a pathway for malicious actors to manipulate the file system.
The technical exploitation of this vulnerability occurs when a local attacker crafts a specially formatted ZIP archive containing file paths that include "../" sequences designed to traverse directory structures. When the WebSphere application processes such an archive through its Enterprise Bundle Archive handling mechanism, the system fails to validate the integrity of the file paths, allowing the attacker to write files to arbitrary locations on the system. This occurs because the application does not properly implement path validation or sanitization during the extraction process, enabling the attacker to bypass normal directory boundaries and potentially overwrite critical system files, create malicious executables, or place backdoors within the application environment. The vulnerability is particularly dangerous in enterprise environments where WebSphere servers often run with elevated privileges and have access to sensitive system resources.
The operational impact of CVE-2018-1797 extends beyond simple unauthorized file access, potentially enabling complete system compromise when combined with other attack vectors. An attacker could leverage this vulnerability to escalate privileges, deploy malicious payloads, or establish persistent access to the affected system. The vulnerability affects the core application server functionality and can be exploited through legitimate administrative processes, making detection more challenging. Organizations running these versions of WebSphere are particularly at risk since the flaw exists in the fundamental archive processing capabilities, potentially allowing attackers to modify critical application components, configuration files, or even system binaries. The vulnerability's classification aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. This weakness creates a direct pathway for attackers to bypass security controls and access unauthorized resources.
Mitigation strategies for CVE-2018-1797 focus on both immediate patching and operational controls to prevent exploitation. IBM released security fixes for all affected versions of WebSphere Application Server, and organizations should prioritize applying these updates to eliminate the vulnerability. Additionally, system administrators should implement strict input validation for all archive processing operations, particularly when handling external or untrusted archives. Network segmentation and privilege separation can help limit the potential impact if exploitation occurs, while monitoring systems should be configured to detect unusual file creation patterns or unexpected directory modifications. The ATT&CK framework categorizes this vulnerability under T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as exploitation typically involves legitimate system accounts and processes to execute malicious payloads. Organizations should also consider implementing automated vulnerability scanning tools that can detect the presence of vulnerable WebSphere versions and ensure proper patch management processes are in place to prevent similar issues in the future.