CVE-2021-43820 Information

Description

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.

CVSS Vector

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

Reference

https://github.com/haiwen/seafile-server/security/advisories/GHSA-m3wc-jv6r-hvv8 https://github.com/haiwen/seafile-server/pull/520

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

5.9