Description
The unserialize() function supported a type code, "S", which was meant to be supported only for APC serialization. This type code allowed arbitrary memory addresses to be accessed as if they were static StringData objects. This issue affected 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.
References (2)
Core 2
Core References
Vendor Advisory x_refsource_confirm
https://hhvm.com/blog/2020/06/30/security-update.html
Patch, Third Party Advisory x_refsource_misc
https://github.com/facebook/hhvm/commit/1107228a5128d3ca1c4add8ac1635d933cbbe2e9
Scores
CVSS v3
7.5
EPSS
0.0122
EPSS Percentile
64.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Details
CWE
CWE-119
CWE-822
Status
published
Products (8)
facebook/hhvm
4.57.0
facebook/hhvm
4.58.0
facebook/hhvm
4.58.1
facebook/hhvm
4.59.0
facebook/hhvm
4.60.0
facebook/hhvm
4.61.0
facebook/hhvm
4.62.0
facebook/hhvm
< 4.32.3
Published
Mar 11, 2021
Tracked Since
Feb 18, 2026