Out-of-bounds Read in Facebook Hhvm

CVE-2019-3557

The implementations of streams for bz2 and php://output improperly implemented their readImpl functions, returning -1 consistently. This behavior caused some stream functions, such as stream_get_line, to trigger an out-of-bounds read when…

Vulnerability class: Buffer Overflow

EPSS: 0.017 (74.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/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-2019-3557?
CVE-2019-3557 is a critical-severity vulnerability in Facebook Hhvm, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2019-01-15.
How severe is CVE-2019-3557?
Critical severity. CVSS v3 base score is 9.8 out of 10.