CVE-2020-10857Network attack vector

Remote code execution via unsafe shell handlers

Published Feb 5, 2021 · Updated Aug 4, 2024

Remote code execution in Zulip Desktop before 5.0.0 allows remote attackers to execute native code through untrusted content. The desktop client passes attacker-influenced external targets and downloaded file paths to Electron shell.openExternal and shell.openItem, causing the operating system to launch them instead of only revealing downloaded files. The path is reachable when attacker-controlled content reaches a connected desktop client, and exploitation runs code with that client's privileges.

CVSS severity9.8
Critical
EPSS probability3.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Zulip Desktop before 5.0.0 allows remote attackers to execute native code through untrusted content. The desktop client passes attacker-influenced external targets and downloaded file paths to Electron shell.openExternal and shell.openItem, causing the operating system to launch them instead of only revealing downloaded files. The path is reachable when attacker-controlled content reaches a connected desktop client, and exploitation runs code with that client's privileges.

The record

CVE
CVE-2020-10857
Published
Feb 5, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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