Buffer overflow in Facebook Hhvm

CVE-2020-1899

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.012 (67.4th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-1899: held from 0.012 to 0.012.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-1899?
CVE-2020-1899 is a high-severity vulnerability in Facebook Hhvm, classified under Untrusted Pointer Dereference. CVSS score: 7.5/10. Published 2021-03-11.
How severe is CVE-2020-1899?
High severity. CVSS v3 base score is 7.5 out of 10.