PHPMailer untrusted code may be run from an overridden address validator
If a function is defined that has the same name as the default built-in email address validation scheme (php), it will be called in default configuration as when no validation scheme is provided, the default scheme's callable php was being called. If an attacker is able to inject such a function into the application (a much bigger issue), it will be called whenever an email address is validated, such as when calling validateAddress().
Impact
Low impact – exploitation requires that an attacker can already inject code into an application, but it provides a trigger pathway.
Patches
This is patched in PHPMailer 6.5.0 by denying the use of simple strings as validator function names, which is a very minor BC break.
Workarounds
Inject your own email validator function.
References
Reported by Vikrant Singh Chauhan via huntr.dev. CVE-2021-3603
For more information
If you have any questions or comments about this advisory:
- Open an issue in the PHPMailer project
- Email us.
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de Composer | phpmailer/phpmailer | < 6.5.0 | 6.5.0 |
Referencias
- https://github.com/PHPMailer/PHPMailer/security/advisories/GHSA-77mr-wc79-m8j3
- https://nvd.nist.gov/vuln/detail/CVE-2021-3603
- https://github.com/PHPMailer/PHPMailer/commit/45f3c18dc6a2de1cb1bf49b9b249a9ee36a5f7f3
- https://github.com/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2021-3603.yaml
- https://github.com/PHPMailer/PHPMailer
- https://github.com/PHPMailer/PHPMailer/releases/tag/v6.5.0
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3YRMWGA4VTMXFB22KICMB7YMFZNFV3EJ
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FJYSOFCUBS67J3TKR74SD3C454N7VTYM
- https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-3603
- https://www.huntr.dev/bounties/1-PHPMailer/PHPMailer
- Vector CVSS
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H- Debilidad (CWE)
CWE-74, CWE-829- Plataforma
- Composer
- Paquete
phpmailer/phpmailer- Publicada
- 22.06.2021
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-77mr-wc79-m8j3 - CC BY 4.0
Historial de vulnerabilidades: phpmailer/phpmailer
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
- 13
- Primera → última
- 12.2016 02.2024
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 2
- Alta 7
- Media 3
- Baja 1
Divulgaciones por año
- 2017: 0
- 2018: 0
- 2019: 0
- 2020: 5
- 2021: 3
- 2022: 2
- 2023: 0
- 2024: 2
- 2025: 0
- 2026: 0
antes: 1
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PHPMailer untrusted code may be run from an overridden address validator esta entrada
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