Out-of-bounds Read in Facebook Hhvm
CVE-2020-1918
In-memory file operations (ie: using fopen on a data URI) did not properly restrict negative seeking, allowing for the reading of memory prior to the in-memory buffer. This issue affects HHVM versions prior to 4.56.3, all versions between 4.57.0 and 4.80.1, all versions between 4.81.0 and 4.93.1, and versions 4.94.0, 4.95.0, 4.96.0, 4.97.0, 4.98.0.
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 (68.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
- Facebook Hhvm — versions 4.98.1, 4.98.0, 4.97.1
Weakness classification (CWE)
References
- hhvm.com/blog/2021/02/25/security-update.html (Release Notes, Vendor Advisory)
- github.com/facebook/hhvm/commit/08193b7f0cd3910256e00d599f0f3eb2519c44ca (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-1918?
- CVE-2020-1918 is a high-severity vulnerability in Facebook Hhvm, classified under Buffer Under-read. CVSS score: 7.5/10. Published 2021-03-10.
- How severe is CVE-2020-1918?
- High severity. CVSS v3 base score is 7.5 out of 10.