SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-1900

When unserializing an object with dynamic properties HHVM needs to pre-reserve the full size of the dynamic property array before inserting anything into it.

CRITICAL 9.8EPSS 1.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

When unserializing an object with dynamic properties HHVM needs to pre-reserve the full size of the dynamic property array before inserting anything into it. Otherwise the array might resize, invalidating previously stored references. This pre-reservation was not occurring in HHVM prior to v4.32.3, between versions 4.33.0 and 4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.38% probability · 71th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
facebook/hhvm
Source
cve-assign@fb.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.