CVE-2021-41270

Published: 24 November 2021

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 `@`.

Priority

Cvss 3 Severity Score

6.5

Score breakdown

Status

Package	Release	Status
symfony Launchpad, Ubuntu, Debian	bionic	Not vulnerable (code not present)
	focal	Released (4.3.8+dfsg-1ubuntu1+esm1) Available with Ubuntu Pro
	hirsute	Ignored (end of life)
	impish	Not vulnerable (5.2.6+dfsg-1ubuntu7)
	jammy	Not vulnerable
	kinetic	Not vulnerable
	lunar	Not vulnerable
	mantic	Not vulnerable
	trusty	Ignored (end of standard support)
	upstream	Released (4.4.19+dfsg-3)
	xenial	Not vulnerable (code not present)
	Patches: upstream: https://github.com/symfony/symfony/commit/3da6f2d45e7536ccb2a26f52fbaf340917e208a8

Severity score breakdown

Parameter	Value
Base score	6.5
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Join the discussion

Canonical is offering Expanded Security Maintenance

Canonical is offering Ubuntu Expanded Security Maintenance (ESM) for security fixes and essential packages.

Find out more about ESM ›