CVE-2020-6811Public exploitNetwork attack vector

Arbitrary command execution via unescaped HTTP method

Published Mar 25, 2020 · Updated Aug 4, 2024

Command injection in Mozilla Firefox before 74, Firefox ESR before 68.6, and Thunderbird before 68.6 allows attackers to execute shell commands. The Copy as cURL builder in devtools/client/shared/curl.js appends a website-controlled HTTP method to the generated command without shell escaping. Exploitation requires a malicious page to create the request and a user to copy it as cURL and paste it into a shell, where commands run with that user's privileges.

CVSS severity8.8
High
EPSS probability3.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Mozilla Firefox before 74, Firefox ESR before 68.6, and Thunderbird before 68.6 allows attackers to execute shell commands. The Copy as cURL builder in devtools/client/shared/curl.js appends a website-controlled HTTP method to the generated command without shell escaping. Exploitation requires a malicious page to create the request and a user to copy it as cURL and paste it into a shell, where commands run with that user's privileges.

The record

CVE
CVE-2020-6811
Published
Mar 25, 2020
Updated
Aug 4, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-77, T1204, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2020CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <74
  2. Affected versionversion=unspecified <ESR68.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <74; version=unspecified <ESR68.6
Mozilla · Thunderbirdversion=unspecified <68.6
Mozilla · Firefox ESRversion=unspecified <68.6

Published CVSS scores

8.3NISTAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1204User Execution
T1059Command and Scripting Interpreter

Public exploit references

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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