CVEvulnerability

CVE-2021-41270

6.5 MEDIUM Published 2021-11-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-11-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0 ([email protected])
4.0 MEDIUM — AV:N/AC:L/Au:S/C:P/I:N/A:N
Weaknesses
CWE-1236

Description

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 configurations

• sensiolabs symfony (>= 4.1.0 < 4.4.35) • sensiolabs symfony (>= 5.0.0 < 5.3.12) • fedoraproject fedora 34 • fedoraproject fedora 35

Related

Weakness · CWE (1)

  • CWE-1236 Improper Neutralization of Formula Elements in a CSV File weakness

References