CVE-2018-6335 Denial of service in HHVM

What is CVE-2018-6335?

CVE-2018-6335 is a high-severity denial of service vulnerability in Facebook HHVM, published on 31 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A Malformed h2 frame can cause 'std::out_of_range' exception when parsing priority meta data. This behavior can lead to denial-of-service. This affects all supported versions of HHVM (3.25.2, 3.24.6, and 3.21.10 and below) when using the proxygen server to handle HTTP2 requests.

Weakness: CWE-20, CWE-400

Which versions are affected by CVE-2018-6335?

It affects 1 product.

Products include Facebook Hhvm.

How do I fix CVE-2018-6335?

No fix has been published for CVE-2018-6335 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2018-6335 being exploited?

There is no known exploitation of CVE-2018-6335 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-3j37-x46m-f23g, UBUNTU-CVE-2018-6335.