Buffer overflow in Facebook Hhvm

CVE-2019-3570

Call to the scrypt_enc() function in HHVM can lead to heap corruption by using specifically crafted parameters (N, r and p). This happens if the parameters are configurable by an attacker for instance by providing the output of scrypt_enc() in a context where Hack/PHP code would attempt to verify it by re-running scrypt_enc() with the same parameters. This could result in information disclosure, memory being overwriten or crashes of the HHVM process. This issue affects versions 4.3.0, 4.4.0, 4.5.0, 4.6.0, 4.7.0, 4.8.0, versions 3.30.5 and below, and all versions in the 4.0, 4.1, and 4.2 series.

Vulnerability class: Buffer Overflow

EPSS: 0.017 (75.3th 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-2019-3570?
CVE-2019-3570 is a critical-severity vulnerability in Facebook Hhvm, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2019-07-18.
How severe is CVE-2019-3570?
Critical severity. CVSS v3 base score is 9.8 out of 10.