CVE-2020-10857
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedZulip Desktop before 5.0.0 improperly uses shell.openExternal and shell.openItem with untrusted content, leading to remote code execution.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceZulip Desktop versions before 5.0.0 contain a vulnerability where the Electron APIs shell.openExternal and shell.openItem are used to handle untrusted content without proper sanitization. These APIs can execute external programs or open files, allowing remote attackers to achieve arbitrary code execution on the affected system.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 5.0.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine installed Zulip Desktop versionOn Windows: Right-click the Zulip Desktop shortcut, select Properties, and check the Details tab for version. On macOS: Right-click the Zulip app in Applications, select Get Info. On Linux: Run 'dpkg -l | grep zulip' or 'rpm -qa | grep zulip' depending on your package manager.Affected if The version displayed is earlier than 5.0.0
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Verify Electron API usage in the applicationInspect the main JavaScript bundle or source code of the Zulip Desktop installation for calls to shell.openExternal or shell.openItem APIs without sanitization routines. The vulnerable code typically handles links or file attachments.Affected if Calls to shell.openExternal or shell.openItem exist without proper input validation or sanitization before version 5.0.0
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Confirm the Zulip Desktop process is running and accessibleOpen Task Manager (Windows), Activity Monitor (macOS), or top/ps (Linux) to verify the Zulip Desktop process is currently active. This confirms the application is installed and in use.Affected if Zulip Desktop process is running and the version is below 5.0.0
A system is affected by CVE-2020-10857 if Zulip Desktop version is earlier than 5.0.0 and the application handles untrusted external links or file attachments using Electron shell APIs.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.0.0
Upgrade Zulip Desktop to version 5.0.0 or later, which properly sanitizes input before passing it to shell.openExternal and shell.openItem APIs.
5.0.0
- Back up any important chats, files, or data from your current Zulip Desktop installation
- Download Zulip Desktop version 5.0.0 or later from the official Zulip download page (zulip.com/download)
- Close any running instances of the Zulip Desktop application
- Install the new version 5.0.0, which will replace the vulnerable installation
- After upgrading, verify the new version by checking Help > About in the desktop app to confirm you are on 5.0.0 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-10857 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-10857 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data