CVE-2021-30477
Last modified
CVE-2021-30477 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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.. EPSS estimates a 0.66% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Zulip | Zulip Server | < 3.4 |
References
- https://blog.zulip.com/2021/04/14/zulip-server-3-4/Release Notes, Vendor Advisory
- https://blog.zulip.com/2021/04/14/zulip-server-3-4/Release Notes, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-30477?
How severe is CVE-2021-30477?
How do I fix CVE-2021-30477?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2021
- CVE-2021-30471A flaw was found in PoDoFo 0.9.7. An uncontrolled recursive …5.5
- CVE-2021-30472A flaw was found in PoDoFo 0.9.7. A stack-based buffer overf…7.8
- CVE-2021-30473aom_image.c in libaom in AOMedia before 2021-04-07 frees mem…9.8
- CVE-2021-30474aom_dsp/grain_table.c in libaom in AOMedia before 2021-03-30…9.8
- CVE-2021-30475aom_dsp/noise_model.c in libaom in AOMedia before 2021-03-24…9.8
- CVE-2021-30476HashiCorp Terraform’s Vault Provider (terraform-provider-vau…9.8
- CVE-2021-30478An issue was discovered in Zulip Server before 3.4. A bug in…4.3
- CVE-2021-30479An issue was discovered in Zulip Server before 3.4. A bug in…5.3
- CVE-2021-3048Certain invalid URL entries contained in an External Dynamic…5.9
- CVE-2021-30480Zoom Chat through 2021-04-09 on Windows and macOS allows cer…8.8
- CVE-2021-30481Valve Steam before 2021-04-17, when a Source engine game is …9
- CVE-2021-30482In JetBrains UpSource before 2020.1.1883, application passwo…7.5
Are you affected by CVE-2021-30477?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST