Vulnerability · Published Apr 14, 2021 · Assigned by mitre

CVE-2021-30477

Medium 4.3

In plain English

A medium-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS NVD)4.3Medium

Exploit odds (30 days)0.7%top 48.4% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

References

https://blog.zulip.com/2021/04/14/zulip-server-3-4/ x_refsource_MISC