CVE-2007-2519 in PEAR
Summary
by MITRE
Directory traversal vulnerability in the installer in PEAR 1.0 through 1.5.3 allows user-assisted remote attackers to overwrite arbitrary files via a .. (dot dot) sequence in the (1) install-as attribute in the file element in package.xml 1.0 or the (2) as attribute in the install element in package.xml 2.0. NOTE: it could be argued that this does not cross privilege boundaries in typical installations, since the code being installed could perform the same actions.
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Analysis
by VulDB Data Team • 01/15/2025
The CVE-2007-2519 vulnerability represents a critical directory traversal flaw within the PEAR package management system, affecting versions 1.0 through 1.5.3. This vulnerability resides in the installer component that processes package.xml configuration files during software installation. The flaw specifically targets the handling of file paths in two distinct XML attributes: the install-as attribute within file elements of package.xml version 1.0 and the as attribute within install elements of package.xml version 2.0. The vulnerability enables malicious actors to manipulate file installation paths through the exploitation of dot-dot sequences that traverse directory structures beyond intended boundaries.
The technical implementation of this vulnerability exploits the insufficient input validation and path sanitization mechanisms within PEAR's installer logic. When processing package.xml files, the installer fails to properly validate or sanitize the path components specified in the targeted attributes, allowing attackers to inject directory traversal sequences such as "../" that can navigate outside the intended installation directory. This flaw operates at the file system level where the installer creates or modifies files based on the paths specified in XML configuration, making it possible to overwrite existing system files or create malicious files in privileged locations. The vulnerability aligns with CWE-22, which specifically addresses directory traversal or path traversal flaws in software systems.
The operational impact of CVE-2007-2519 extends beyond simple file overwrites, potentially enabling attackers to compromise entire systems through strategic file manipulation. While the vulnerability description notes that it may not cross traditional privilege boundaries in typical installations, the implications remain severe as attackers can leverage this weakness to modify critical system files, inject malicious code into installed packages, or manipulate the installation process to achieve unauthorized system access. The vulnerability can be exploited through user-assisted remote attacks, meaning that an attacker needs only to convince a user to install a malicious package, which then executes the directory traversal during the installation phase. This attack vector aligns with ATT&CK technique T1068, which covers local privilege escalation through the exploitation of software vulnerabilities.
Mitigation strategies for this vulnerability require immediate patching of affected PEAR installations to versions beyond 1.5.3 where the directory traversal protections have been implemented. System administrators should also implement strict package source verification and code review processes for all PEAR packages before installation, particularly for packages from untrusted sources. Additional protective measures include restricting write permissions on system directories where PEAR packages are installed, implementing proper input validation at multiple layers of the installation process, and monitoring for unauthorized file modifications. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation, as the vulnerability could be leveraged as a stepping stone for broader system compromise. The remediation process should include comprehensive vulnerability scanning to identify any systems that may have been compromised through prior exploitation of this vulnerability.