CVE-2020-1919: facebook hhvm Out-of-bounds Read
Vulnerability summary
CVE-2020-1919 is a high (CVSS 7.5) Out-of-bounds Read vulnerability in facebook hhvm. EPSS estimates a 1.22% chance of exploitation in the next 30 days, higher than 68.1% of scored vulnerabilities.
Timeline
- 10-03-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
Incorrect bounds calculations in substr_compare could lead to an out-of-bounds read when the second string argument passed in is longer than the first. 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.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
1.22%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
0.00 pp
From 1.22% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Facebook1 product
- hhvm≥ 4.81.0, < unspecified | ≥ 4.57.0, < unspecified | ≥ unspecified, < 4.56.3 | < 4.56.3 | ≥ 4.57.0, < 4.80.2 | ≥ 4.81.0, < 4.93.2 | 4.94.0 | 4.95.0 | 4.96.0 | 4.97.0 | 4.98.0
Ubuntu1 product
- hhvmAll versions (No fix recorded)
2 vendors · 2 products
References
4 links- github.com/facebook/hhvm/commit/08193b7f0cd3910256e00d599f0f3eb2519c44caX Refsource MISCREPORTPatchThird Party Advisory