CVE-2019-3556: Path Traversal
HHVM supports the use of an "admin" server which accepts administrative requests over HTTP. One of those request handlers, dump-pcre-cache, can be used to output cached regular expressions from the current execution context into a file. The handler takes a parameter which specifies where on the filesystem to write this data. The parameter is not validated, allowing a malicious user to overwrite arbitrary files where the user running HHVM has write access. This issue affects HHVM versions prior to 4.56.2, all versions between 4.57.0 and 4.78.0, as well as 4.79.0, 4.80.0, 4.81.0, 4.82.0, and 4.83.0.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2019-3556?
The severity of CVE-2019-3556 is high with a CVSS score of 8.1.
How does CVE-2019-3556 affect HHVM?
CVE-2019-3556 affects HHVM versions up to and including 4.56.2, as well as versions between 4.57.0 and 4.78.0.
What is the vulnerability in HHVM related to CVE-2019-3556?
The vulnerability in HHVM related to CVE-2019-3556 is the use of an "admin" server that accepts administrative requests over HTTP.
How can an attacker exploit CVE-2019-3556?
An attacker can exploit CVE-2019-3556 by sending a malicious request to the dump-pcre-cache request handler, which outputs cached regular expressions into a file.
Is there a fix available for CVE-2019-3556?
Yes, a fix is available for CVE-2019-3556. It is recommended to update to a version of HHVM that is not affected by the vulnerability.