TI-2020-01844 Aliases CVE-2020-1917 GHSA-gf82-22g8-prc5

Heap-based buffer overflow in Meta HHVM

MEDIUM 45CWE-122Published 2021-03-10 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

xbuf_format_converter, used as part of exif_read_data, was appending a terminating null character to the generated string, but was not using its standard append char function. As a result, if the buffer was full, it would result in an out-of-bounds write. 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.

Why it matters now

EPSS 0.01384 72nd percentileScored 2026-11-07

Fix Fixed HHVM (Facebook): 4.98.1, 4.97.1, 4.96.1 +5

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Meta	HHVM	4.98.0; 4.97.0; 4.96.0; 4.95.0; 4.94.0; 4.81.0 and later; 4.57.0 and later; before 4.56.3	4.98.1, 4.97.1, 4.96.1, 4.95.1, 4.94.1, 4.93.2, 4.80.2, 4.56.3	Patch available	CNA

HHVM VendorMeta Affected 4.98.0; 4.97.0; 4.96.0; 4.95.0; 4.94.0; 4.81.0 and later; 4.57.0 and later; before 4.56.3 Fixed in 4.98.1, 4.97.1, 4.96.1, 4.95.1, 4.94.1, 4.93.2, 4.80.2, 4.56.3 Patch available CNA

CPE configurations NVD · 6

CPE	Versions	Role	Vendor
cpe:2.3:a:facebook:hhvm::::::::	before 4.56.3; 4.57.0 to before 4.80.2; 4.81.0 to before 4.93.2	Vulnerable	Meta
cpe:2.3:a:facebook:hhvm:4.94.0:::::::*	4.94.0	Vulnerable	Meta
cpe:2.3:a:facebook:hhvm:4.95.0:::::::*	4.95.0	Vulnerable	Meta
cpe:2.3:a:facebook:hhvm:4.96.0:::::::*	4.96.0	Vulnerable	Meta
cpe:2.3:a:facebook:hhvm:4.97.0:::::::*	4.97.0	Vulnerable	Meta
cpe:2.3:a:facebook:hhvm:4.98.0:::::::*	4.98.0	Vulnerable	Meta

cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:* Versions before 4.56.3; 4.57.0 to before 4.80.2; 4.81.0 to before 4.93.2 Vulnerable ·Meta
cpe:2.3:a:facebook:hhvm:4.94.0:*:*:*:*:*:*:* Versions 4.94.0 Vulnerable ·Meta
cpe:2.3:a:facebook:hhvm:4.95.0:*:*:*:*:*:*:* Versions 4.95.0 Vulnerable ·Meta
cpe:2.3:a:facebook:hhvm:4.96.0:*:*:*:*:*:*:* Versions 4.96.0 Vulnerable ·Meta
cpe:2.3:a:facebook:hhvm:4.97.0:*:*:*:*:*:*:* Versions 4.97.0 Vulnerable ·Meta
cpe:2.3:a:facebook:hhvm:4.98.0:*:*:*:*:*:*:* Versions 4.98.0 Vulnerable ·Meta

Remediation

Fix · CNA HHVM (Facebook) Fixed in 4.98.1, 4.97.1, 4.96.1, 4.95.1, 4.94.1, 4.93.2, 4.80.2, 4.56.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2021-03-10
Facebook HHVM 4.56.3, unspecified
5 records Highest priority Priority MEDIUM 2 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2021-06342 Heap-based buffer overflow in Meta HHVMPriority MEDIUM 45
- TI-2020-01848 Stack-based buffer overflow in Meta HHVMPriority LOW 35
- TI-2020-01846 Out-of-bounds read in Meta HHVMPriority LOW 35
Show all 5 records →

Timeline

2026-10-02 Threatist record created from CVE-2020-1917
2026-10-03 Alias added: GHSA-gf82-22g8-prc5

References

Patch 1

https://github.com/facebook/hhvm/commit/08193b7f0cd3910256e00d599f0f3eb2519c44ca

Advisory 1

https://hhvm.com/blog/2021/02/25/security-update.html

TI-2018-04659 Improper input validation in Meta HHVM CVSS 3.1CRITICAL 9.8
TI-2022-17147 Broken or risky cryptographic algorithm in Meta HHVM CVSS 3.1CRITICAL 9.8
TI-2019-08934 Memory corruption in Meta HHVM CVSS 3.1CRITICAL 9.8
TI-2021-06352 Heap-based buffer overflow in Meta folly CVSS 3.1CRITICAL 9.8
TI-2019-08935 An invalid free in mb_detect_order can cause the application to crash or potentially… CVSS 3.1CRITICAL 9.8
TI-2016-05898 Integer overflow in bcmath in Facebook HHVM before 3.15.0 allows attackers to have… CVSS 3.0CRITICAL 9.8

See all 39 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences