CVEvulnerability
CVE-2021-41270
6.5 MEDIUM
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
- https://github.com/symfony/symfony/commit/3da6f2d45e7536ccb2a26f52fbaf340917e208a8 Patch, Third Party Advisory
- https://github.com/symfony/symfony/pull/44243 Patch, Third Party Advisory
- https://github.com/symfony/symfony/releases/tag/v5.3.12 Release Notes, Third Party Advisory
- https://github.com/symfony/symfony/security/advisories/GHSA-2xhg-w2g5-w95x Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3BPT4SF6SIXFMZARDWED5T32J7JEH3EP/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QSREFD2TJT5LWKM6S4MD3W26NQQ5WJUP/ lists.fedoraproject.org
- https://github.com/symfony/symfony/commit/3da6f2d45e7536ccb2a26f52fbaf340917e208a8 Patch, Third Party Advisory
- https://github.com/symfony/symfony/pull/44243 Patch, Third Party Advisory
- https://github.com/symfony/symfony/releases/tag/v5.3.12 Release Notes, Third Party Advisory
- https://github.com/symfony/symfony/security/advisories/GHSA-2xhg-w2g5-w95x Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3BPT4SF6SIXFMZARDWED5T32J7JEH3EP/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QSREFD2TJT5LWKM6S4MD3W26NQQ5WJUP/ lists.fedoraproject.org