CVE-2021-43820
Publication date 14 December 2021
Last updated 24 July 2024
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| seafile | 22.04 LTS jammy |
Not affected
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support |
Notes
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.9 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |