TI-2021-19151 Aliases CVE-2021-43099 GHSA-g5mc-2cpg-f638

An Archive Extraction (AKA "Zip Slip) vulnerability exists in bbs 5.3 in the UpgradeNow…

LOW 25CWE-22Published 2022-03-28 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: High
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · High · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

An Archive Extraction (AKA "Zip Slip) vulnerability exists in bbs 5.3 in the UpgradeNow function in UpgradeManageAction.java, which unzips the arbitrary upladed zip file without checking filenames. The vulnerability is exploited using a specially crafted archive that holds directory traversal filenames (e.g. ../../evil.exe).

Why it matters now

EPSS 0.01109 66th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix No fix listed No fixed version in the sources yet

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
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:diyhi:bbs:5.3:::::::*	5.3	Vulnerable	diyhi

cpe:2.3:a:diyhi:bbs:5.3:*:*:*:*:*:*:* Versions 5.3 Vulnerable ·diyhi

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-43099
2026-10-03 Alias added: GHSA-g5mc-2cpg-f638

References

Exploit 1

https://github.com/diyhi/bbs/issues/51

TI-2025-08670 diyhi bbs File Compression FilePackageManageAction.java information disclosure CVSS 4.0MEDIUM 5.3
TI-2025-06142 diyhi bbs HTTP Header login getUrl server-side request forgery CVSS 4.0MEDIUM 5.3
TI-2025-05854 diyhi bbs API ForumManageAction.java add path traversal CVSS 4.0MEDIUM 5.3
TI-2021-19149 A Server-side Template Injection (SSTI) vulnerability exists in bbs 5.3 in… CVSS 3.1HIGH 7.2
TI-2021-19155 A File Upload vulnerability exists in bbs 5.3 is via ForumManageAction.java in a GetType… CVSS 3.1HIGH 7.2
TI-2021-19154 A File Upload vulnerability exists in bbs 5.3 is via HelpManageAction.java in a GetType… CVSS 3.1HIGH 7.2

See all 9 →

Sources

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