CVE-2021-32703
Lack of ratelimit on shareinfo endpoint
In short
The shareinfo endpoint in Nextcloud Server lacks rate limiting, allowing attackers to quickly guess and enumerate valid share tokens. This enables unauthorized access to shared files or folders.
Technical detail
The shareinfo endpoint fails to implement rate limiting controls (CWE-799), permitting an unauthenticated attacker to perform brute-force enumeration of share tokens through rapid sequential requests. Successful token enumeration grants access to shared resources without authorization.
Summary generated and translated by AI from the official description.
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, there was a lack of ratelimiting on the shareinfo endpoint. This may have allowed an attacker to enumerate potentially valid share tokens. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
nextcloud · security-advisoriesWant to know if your infrastructure is exposed to this?
Talk to TrueHacking →References
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-375p-cxxq-gc9phttps://github.com/nextcloud/server/pull/26945https://hackerone.com/reports/1173684https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BVZS26RDME2DYTKET5AECRIZDFUGR2AZ/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J63NBVPR2AQCAWRNDOZSGRY5II4WS2CZ/https://security.gentoo.org/glsa/202208-17