7.5

CVE-2020-1918: facebook hhvm Buffer Under-read

CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2020-1918
Published 10-03-2021Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2020-1918 is a high (CVSS 7.5) Buffer Under-read vulnerability in facebook hhvm. EPSS estimates a 1.22% chance of exploitation in the next 30 days, higher than 68.2% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
1.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 10-03-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

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 20-09-2026

20-09-202620-10-2026
EPSS score
1.22%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected 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