What is the CVSS score of CVE-2021-41270?

CVE-2021-41270 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N. EPSS exploitation probability: 1.4%.

Is there a patch available for CVE-2021-41270?

Yes, a patch is available for CVE-2021-41270. Update the affected software to the latest version immediately.

PHP CVE-2021-41270

MEDIUM

Improper Neutralization of Formula Elements in a CSV File (CWE-1236)

2021-11-24 security-advisories@github.com

PHP Code Injection Symfony Fedora

6.5

CVSS 3.1 · Vendor: github

Severity by source

Vendor (github) PRIMARY

6.5 MEDIUM

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Primary rating from Vendor (github) · only source for this CVE.

CVSS VectorVendor: github

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

CVE Published

Nov 24, 2021 - 19:15 cve.org

MEDIUM 6.5

DescriptionCVE.org

Symfony/Serializer handles serializing and deserializing data structures for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Symfony versions 4.1.0 before 4.4.35 and versions 5.0.0 before 5.3.12 are vulnerable to CSV injection, also known as formula injection. In Symfony 4.1, maintainers added the opt-in csv_escape_formulas option in the CsvEncoder, to prefix all cells starting with =, +, - or @ with a tab \t. Since then, OWASP added 2 chars in that list: Tab (0x09) and Carriage return (0x0D). This makes the previous prefix char (Tab \t) part of the vulnerable characters, and OWASP suggests using the single quote ' for prefixing the value. Starting with versions 4.4.34 and 5.3.12, Symfony now follows the OWASP recommendations and uses the single quote ' to prefix formulas and add the prefix to cells starting by \t, \r as well as =, +, - and @.

AnalysisAI

Symfony/Serializer handles serializing and deserializing data structures for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.

Technical ContextAI

This vulnerability is classified under CWE-1236. Symfony/Serializer handles serializing and deserializing data structures for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Symfony versions 4.1.0 before 4.4.35 and versions 5.0.0 before 5.3.12 are vulnerable to CSV injection, also known as formula injection. In Symfony 4.1, maintainers added the opt-in csv_escape_formulas option in the CsvEncoder, to prefix all cells starting with =, +, - or @ with a tab \t. Since then, OWASP added 2 chars in that list: Tab (0x09) and Carriage return (0x0D). This makes the previous prefix char (Tab \t) part of the vulnerable characters, and OWASP suggests using the single quote ' for prefixing the value. Starting with versions 4.4.34 and 5.3.12, Symfony now follows the OWASP recommendations and uses the single quote ' to prefix formulas and add the prefix to cells starting by \t, \r as well as =, +, - and @. Affected products include: Sensiolabs Symfony, Fedoraproject Fedora. Version information: before 4.4.35.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.