CVE-2021-3779

Ruby-MySQL Gem Client File Read

6.5 MediumFix available

A malicious MySQL server can request local file content from a client using ruby-mysql prior to version 2.10.0 without explicit authorization from the user. This issue was resolved in version 2.10.0 and later.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

1.19%Up 0.3 points since Jun 29, 2022

What each source reports

NVD Score used 6.5

Record: CVE-2021-3779
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:P/I:N/A:N
Weakness: CWE-610
Updated: 2026-11-02

CVE List No score

Ruby-MySQL Gem Client File Read

Record: CVE-2021-3779
Weakness: CWE-610
Updated: 2026-11-02

EUVDEUVD-2022-5970 No score

Record: EUVD-2022-5970
Updated: 2026-11-03

GitHub AdvisoriesGHSA-73pr-g6jj-5hc9 6.5

Externally Controlled Reference to a Resource in Another Sphere in ruby-mysql

A malicious actor can read arbitrary files from a client that uses ruby-mysql to communicate to a rogue MySQL server and issue database queries. In these cases, the server has the option to create a database reply using the LOAD DATA LOCAL statement, which instructs the client to provide additional data from a local file readable by the client (and not a "local" file on the server).

Record: GHSA-73pr-g6jj-5hc9
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Weakness: CWE-610
Updated: 2026-11-02

OSVGHSA-73pr-g6jj-5hc9 6.5

Externally Controlled Reference to a Resource in Another Sphere in ruby-mysql

Record: GHSA-73pr-g6jj-5hc9
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Weakness: CWE-610
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-3779 6.5

Record: UBUNTU-CVE-2021-3779
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`ruby-mysql` RubyGems	before 2.10.0	2.10.0
`ruby-mysql` RubyGems	before 2.10.0, plus listed versions 2.9.02.9.12.9.102.9.112.9.12 Show 10 moreShow less 2.9.132.9.142.9.22.9.32.9.42.9.52.9.62.9.72.9.82.9.9	2.10.0
`ruby-mysql` Ubuntu:16.04:LTS	All versions, plus listed versions 2.9.1-1build22.9.1-1build32.9.1-1build42.9.1-1build52.9.1-1ubuntu1	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-3779 is a medium vulnerability (CVSS 6.5) in Ruby-mysql Project Ruby-mysql, published June 28, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.19%, the 68th percentile. Fixed in ruby-mysql 2.10.0.