CVE-2004-0630 in Acrobat
Summary
by MITRE
The uudecoding feature in Adobe Acrobat Reader 5.0.5 and 5.0.6 for Unix and Linux, and possibly other versions including those before 5.0.9, allows remote attackers to execute arbitrary code via shell metacharacters ("`" or backtick) in the filename of the PDF file that is provided to the uudecode command.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 03/09/2021
The vulnerability described in CVE-2004-0630 represents a critical security flaw in Adobe Acrobat Reader's handling of uuencoded data on Unix and Linux systems. This issue specifically affects versions 5.0.5 and 5.0.6, with potential impacts extending to earlier releases up to version 5.0.8. The flaw resides in the application's uudecoding functionality which processes uuencoded attachments within PDF files, creating a pathway for remote code execution through carefully crafted malicious inputs.
The technical mechanism behind this vulnerability involves the improper handling of shell metacharacters within filename parameters during the uudecoding process. When a PDF file containing uuencoded data is opened, the Acrobat Reader application executes the uudecode command to process the encoded content. However, the application fails to properly sanitize or escape special characters in the filename field, allowing attackers to inject shell metacharacters such as backticks or grave accents. These characters are interpreted by the shell as command substitution operators, enabling arbitrary command execution with the privileges of the user running Acrobat Reader.
This vulnerability directly maps to CWE-78, which describes improper neutralization of special elements used in OS commands, and represents a classic command injection attack vector. The operational impact of this flaw is severe as it allows remote attackers to execute arbitrary code on vulnerable systems without requiring any local privileges or user interaction beyond opening a malicious PDF file. The attack can be executed over a network connection, making it particularly dangerous in enterprise environments where users frequently open PDF documents from untrusted sources.
The exploitation of this vulnerability follows established patterns documented in the MITRE ATT&CK framework under the technique of command injection, specifically targeting the execution of arbitrary commands through compromised applications. Attackers can leverage this weakness to gain unauthorized access to systems, escalate privileges, or deploy additional malicious payloads. The vulnerability affects not just individual user systems but also corporate networks where Acrobat Reader is widely deployed, potentially enabling lateral movement and persistent access to sensitive organizational resources.
Mitigation strategies for CVE-2004-0630 include immediate upgrading to Adobe Acrobat Reader version 5.0.9 or later, which contains the necessary patches to address the uudecoding vulnerability. Organizations should also implement network-based protections such as PDF content filtering and sandboxing mechanisms to prevent execution of potentially malicious PDF files. Additionally, system administrators should consider disabling uudecoding functionality in Acrobat Reader where it is not required, and implement proper input validation and sanitization practices for all file processing operations. Regular security assessments and vulnerability management programs should be employed to identify and remediate similar issues in other applications that may be susceptible to command injection attacks through improper shell metacharacter handling.