Horizon Alert
Summary of the vulnerability and why it matters
An issue in PHP's PHAR extension could allow an attacker to read sensitive information from memory. This is important because it could expose confidential data when processing file names or uploaded files.
- Can lead to disclosure of sensitive information.
- Affects applications processing files.
- Reachable from the internet.
Attack Path
How an attacker could exploit the issue
An attacker can exploit this vulnerability by sending a specially crafted file name to a PHP application that processes PHAR archives. This could allow them to read sensitive information from memory, potentially leading to further compromise.
- No authentication required.
- Targets PHAR file processing.
- Requires user-supplied file name.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability in PHP's PHAR extension allows attackers to read memory beyond allocated data, which could lead to information disclosure or crashes. Given that PHP is extensively used in web applications, and this flaw is reachable through file parsing, exploitation is a plausible threat, especially if public exploit code emerges.
- PHAR parsing affects file handling.
- No public exploit reported yet.
- Published in early 2019.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
Prioritize updating PHP to versions 5.6.40, 7.1.26, 7.2.14, or 7.3.1, as this critical vulnerability allows unauthenticated attackers to read sensitive memory. If immediate patching is not possible, isolate affected systems from untrusted networks to prevent exploitation.
- Update PHP to latest patch version.
- Isolate vulnerable services if patching is delayed.
- Monitor for unexpected memory reads.
