SB2019092731 - Multiple vulnerabilities in phpBB

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-ID: CVE-2019-16108)

The vulnerability allows a remote non-authenticated attacker to manipulate data.

phpBB 3.2.7 allows adding an arbitrary Cascading Style Sheets (CSS) token sequence to a page through BBCode.

2) Cross-site request forgery (CVE-ID: CVE-2019-16107)

The vulnerability allows a remote attacker to perform cross-site request forgery attacks.

The vulnerability exists due to insufficient validation of the HTTP request origin. A remote attacker can trick the victim to visit a specially crafted web page and perform arbitrary actions on behalf of the victim on the vulnerable website.

3) Cross-site scripting (CVE-ID: CVE-2019-13376)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can permanently inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Remediation

Install update from vendor's website.

References

• https://www.phpbb.com/community/viewtopic.php?t=2523271
• https://www.phpbb.com/community/viewforum.php?f=14
• https://blog.phpbb.com/category/security/
• https://ssd-disclosure.com/archives/4007/ssd-advisory-phpbb-csrf-token-hijacking-leading-to-stored-xss