CVE-2021-30477

EUVD-2021-17400
An issue was discovered in Zulip Server before 3.4. A bug in the implementation of replies to messages sent by outgoing webhooks to private streams meant that an outgoing webhook bot could be used to send messages to private streams that the user was not intended to be able to send messages to.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 45%
Affected Products (NVD)
VendorProductVersion
zulipzulip_server
𝑥
< 3.4
𝑥
= Vulnerable software versions
References
https://blog.zulip.com/2021/04/14/zulip-server-3-4/
https://blog.zulip.com/2021/04/14/zulip-server-3-4/