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Elvish vulnerable to remote code execution via the web UI backend

High severity GitHub Reviewed Published Sep 21, 2021 in elves/elvish • Updated Jan 27, 2023

Package

gomod github.com/elves/elvish (Go)

Affected versions

< 0.14.0

Patched versions

0.14.0

Description

Impact

Elvish's backend for the experimental web UI (started by elvish -web) hosts an endpoint that allows executing the code sent from the web UI.

The backend does not check the origin of requests correctly. As a result, if the user has the web UI backend open and visits a compromised or malicious website, the website can send arbitrary code to the endpoint in localhost.

Patches

All Elvish releases since 0.14.0 no longer include the experimental web UI, although it is still possible for the user to build a version from source that includes it.

The issue can be patched for previous versions by removing the web UI (found in web, pkg/web or pkg/prog/web, depending on the exact version).

Workarounds

Do not use the experimental web UI.

For more information

If you have any questions or comments about this advisory, please email xiaqqaix@gmail.com.

References

@xiaq xiaq published to elves/elvish Sep 21, 2021
Published by the National Vulnerability Database Sep 23, 2021
Reviewed Sep 23, 2021
Published to the GitHub Advisory Database Sep 23, 2021
Last updated Jan 27, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H

EPSS score

0.195%
(57th percentile)

Weaknesses

CVE ID

CVE-2021-41088

GHSA ID

GHSA-fpv6-f8jw-rc3r

Source code

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