CVE-2021-43820 HIGH

CVE-2021-43820: Permissions check bypass in Seafile

Vendor Haiwen
Product seafile-server
Weakness CWE-639 · IDOR
Published December 14, 2021
Last update August 4, 2024

CVSS base score

7.4/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Seafile is an open source cloud storage system. A sync token is used in Seafile file syncing protocol to authorize access to library data. To improve performance, the token is cached in memory in seaf-server. Upon receiving a token from sync client or SeaDrive client, the server checks whether the token exist in the cache. However, if the token exists in cache, the server doesn't check whether it's associated with the specific library in the URL. This vulnerability makes it possible to use any valid sync token to access data from any **known** library. Note that the attacker has to first find out the ID of a library which it has no access to. The library ID is a random UUID, which is not possible to be guessed. There are no workarounds for this issue.

Key dates

02Disclosure timeline

December 14, 2021 CVE published
August 4, 2024 Record updated