CVE-2021-30477 Missing authorization in n/a
Outgoing webhook bots can bypass restrictions to send messages to private streams, allowing unauthorized access to private data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-30477?
CVE-2021-30477 is a medium-severity missing authorization vulnerability in n/a, published on 14 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2021-30477?
It affects 1 product.
Products include Zulip Zulip Server.
How do I fix CVE-2021-30477?
No fix has been published for CVE-2021-30477 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-30477 being exploited?
There is no known exploitation of CVE-2021-30477 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2019-18933 Information disclosure in n/a
- CVE-2020-15070 Code injection in n/a
- CVE-2017-0910 Missing authorization in Zulip Server
- CVE-2025-31478 Zulip Authentication Backend Configuration Bypass
- CVE-2023-33186 Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip
Sources
Also known as GHSA-45v2-23j7-x684.