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 operating on such malformed streams. The implementations were updated to return valid values consistently. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).
Vulnerability class: Buffer Overflow
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.017 (77.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 77.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000
Affected products
- Facebook Hhvm — versions 3.30.1, 3.30.0, 3.27.5
Weakness classification (CWE)
References
- hhvm.com/blog/2019/01/14/hhvm-3.30.2.html (Vendor Advisory)
- github.com/facebook/hhvm/commit/6e4dd9ec3f14b48170fc45dc9d13a3261765f994 (Patch, Third Party Advisory)
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.