GHSA-2xhg-w2g5-w95x

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GHSA-2xhg-w2g5-w95x

Summary: CSV Injection in symfony/serializer

Details: 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](https://owasp.org/www-community/attacks/CSV_Injection) 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](https://github.com/symfony/symfony/commit/3da6f2d45e7536ccb2a26f52fbaf340917e208a8) for branch 4.4. Credits ------- We would like to thank Jake Barwell for reporting the issue and Jérémy Derussé for fixing the issue.

References: 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/[email protected]/message/3BPT4SF6SIXFMZARDWED5T32J7JEH3EP, https://lists.fedoraproject.org/archives/list/[email protected]/message/QSREFD2TJT5LWKM6S4MD3W26NQQ5WJUP, https://symfony.com/cve-2021-41270