Is CVE-2021-30477 in the CISA KEV catalog?

No. CVE-2021-30477 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-30477?

CVE-2021-30477 has a CVSS v3 base score of 4.3 (MEDIUM).

What is the EPSS score for CVE-2021-30477?

CVE-2021-30477 has an EPSS score of 0.66% (47th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-30477?

Upgrade zulip server to 3.4 or later.

CVE & CISA-KEV Catalog

CVE-2021-30477

MEDIUM

4.3

CVSS v3

NVD

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.

How to fix

Remediation Available

zulip serverNVD

Affected:< 3.4Fixed in:3.4CVE-2021-30477derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Exploit Intelligence

0.66%probability of exploitation in 30 days

47thpercentile

Moderate risk: more likely to be exploited than 47% of all known CVEs.

References

Vendor Advisory1

blog.zulip.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.