VULNERABILITY INTELLIGENCE

CVE-2020-1899

CVSS score7.5 HIGH

EPSS probability1.22%

CISA KEVNot currently listed

Published2021-03-11

Last modified2026-06-17

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Description

The unserialize() function supported a type code, "S", which was meant to be supported only for APC serialization. This type code allowed arbitrary memory addresses to be accessed as if they were static StringData objects. This issue affected HHVM prior to v4.32.3, between versions 4.33.0 and 4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.

Weakness classification

cve-assign@fb.com: CWE-822
nvd@nist.gov: CWE-119

Primary references

cve-assign@fb.com — Patch, Third Party Advisory
cve-assign@fb.com — Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory