CVE-2021-43099

4.9 mediumEPSS 1.1%

Medium (4.9) in diyhi bbs. EPSS 1.1% chance of exploitation in the next 30 days.

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).

Severity

CVSS 3.1

4.9 medium

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

EPSS: 1.1% chance of exploitation in the next 30 days; higher than 65% of CVEs (scores of 2026-10-31)
CWE: CWE-22
Published: 2022-03-28
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

diyhi:bbs

References

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

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