Buffer overflow in Facebook Hhvm

CVE-2021-24025

Due to incorrect string size calculations inside the preg_quote function, a large input string passed to the function can trigger an integer overflow leading to a heap overflow. This issue affects HHVM versions prior to 4.56.3, all versions between 4.57.0 and 4.80.1, all versions between 4.81.0 and 4.93.1, and versions 4.94.0, 4.95.0, 4.96.0, 4.97.0, 4.98.0.

Vulnerability class: Buffer Overflow

EPSS: 0.017 (75.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-24025?
CVE-2021-24025 is a critical-severity vulnerability in Facebook Hhvm, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2021-03-10.
How severe is CVE-2021-24025?
Critical severity. CVSS v3 base score is 9.8 out of 10.