SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-41270

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.

MEDIUM 6.5EPSS 1.35%

Does this matter?

Lower severity and a low EPSS score (1.35%). Track it; it rarely justifies an emergency change on its own.

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 `@`.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS
1.35% probability · 70th percentile
CISA KEV
Not listed
Weakness
CWE-1236
Affected
sensiolabs/symfony · fedoraproject/fedora
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.