CVE-2019-3556 Path traversal in HHVM

What is CVE-2019-3556?

CVE-2019-3556 is a high-severity path traversal vulnerability in Facebook HHVM, published on 26 Oct 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-22

Which versions are affected by CVE-2019-3556?

It affects 1 product.

Products include Facebook Hhvm.

How do I fix CVE-2019-3556?

No fix has been published for CVE-2019-3556 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2019-3556 being exploited?

There is no known exploitation of CVE-2019-3556 in the wild and no public exploit code.

Other vulnerabilities in Facebook HHVM

• CVE-2022-36937 HHVM 4.172.0 and all prior versions use TLS 1.0 for secure connections when handling tls:// URLs in the stream extension. Critical 9.8
• CVE-2020-1900 Use after free in HHVM Critical 9.8
• CVE-2020-1916 Integer overflow in HHVM Critical 9.8
• CVE-2020-1917 Memory corruption in HHVM Critical 9.8
• CVE-2021-24025 Integer overflow in HHVM Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-36h6-q98c-7j6j, UBUNTU-CVE-2019-3556.