CSV Injection in symfony/serializer
Description
CSV Injection, also known as Formula Injection, occurs when websites embed untrusted input inside CSV files. When a spreadsheet program opens a CSV, any cell starting with = is interpreted by the software as a formula and could be abused by an attacker.
In Symfony 4.1, we've added the opt-in csv_escape_formulas option in CsvEncoder, to prefix all cells starting by =, +, - or @ by a tab \t.
Since then, OWASP added 2 chars in that list:
- Tab (0x09)
- Carriage return (0x0D)
This makes our previous prefix char (Tab \t) part of the vulnerable characters, and OWASP suggests using the single quote ' for prefixing the value.
Resolution
Symfony now follows the OWASP recommendations and use the single quote ' to prefix formulas and adds the prefix to cells starting by \t, \r as well as =, +, - and @.
The patch for this issue is available here for branch 4.4.
Credits
We would like to thank Jake Barwell for reporting the issue and Jérémy Derussé for fixing the issue.
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de Composer | symfony/serializer | >= 5.0.0, < 5.3.12, >= 4.1.0, < 4.4.35 | 5.3.12, 4.4.35 |
| Paquete de Composer | symfony/symfony | >= 4.1.0, < 4.4.35, >= 5.0.0, < 5.3.12 | 4.4.35, 5.3.12 |
Referencias
- https://github.com/symfony/symfony/security/advisories/GHSA-2xhg-w2g5-w95x
- https://nvd.nist.gov/vuln/detail/CVE-2021-41270
- https://github.com/symfony/symfony/pull/44243
- https://github.com/symfony/symfony/commit/3da6f2d45e7536ccb2a26f52fbaf340917e208a8
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/serializer/CVE-2021-41270.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2021-41270.yaml
- https://github.com/symfony/symfony
- https://github.com/symfony/symfony/releases/tag/v5.3.12
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3BPT4SF6SIXFMZARDWED5T32J7JEH3EP
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QSREFD2TJT5LWKM6S4MD3W26NQQ5WJUP
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3BPT4SF6SIXFMZARDWED5T32J7JEH3EP
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QSREFD2TJT5LWKM6S4MD3W26NQQ5WJUP
- https://symfony.com/cve-2021-41270
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N- Debilidad (CWE)
CWE-1236- Plataforma
- Composer
- Paquete
symfony/serializer, symfony/symfony- Publicada
- 24.11.2021
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-2xhg-w2g5-w95x - CC BY 4.0
Historial de vulnerabilidades: symfony/serializer
Todas las vulnerabilidades publicadas de este paquete (Paquete de Composer), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 2
- Primera → última
- 11.2021 05.2024
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 1
- Media 1
Divulgaciones por año
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 0
-
CSV Injection in symfony/serializer esta entrada
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