CVE-2020-1893 Denial of service in HHVM

What is CVE-2020-1893?

CVE-2020-1893 is a high-severity denial of service vulnerability in Facebook HHVM, published on 3 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Insufficient boundary checks when decoding JSON in TryParse reads out of bounds memory, potentially leading to DOS. This issue affects HHVM 4.45.0, 4.44.0, 4.43.0, 4.42.0, 4.41.0, 4.40.0, 4.39.0, versions between 4.33.0 and 4.38.0 (inclusive), versions between 4.9.0 and 4.32.0 (inclusive), and versions prior to 4.8.7.

Weakness: CWE-125

Which versions are affected by CVE-2020-1893?

It affects 1 product.

Products include Facebook Hhvm.

How do I fix CVE-2020-1893?

No fix has been published for CVE-2020-1893 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-2020-1893 being exploited?

There is no known exploitation of CVE-2020-1893 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-m8q8-334f-8qxg, UBUNTU-CVE-2020-1893.