CVE-2023-48115 in SmarterMail
Summary
by MITRE • 12/21/2023
SmarterTools SmarterMail 16.x 8495 through 8664 before 8747 allows stored DOM XSS because an XSS protection mechanism is skipped when messageHTML and messagePlainText are set in the same request.
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Analysis
by VulDB Data Team • 01/14/2024
The vulnerability identified as CVE-2023-48115 affects SmarterTools SmarterMail versions ranging from 16.x build 8495 through 8664 before 8747, representing a critical stored cross-site scripting flaw that undermines the application's security posture. This vulnerability specifically exploits a weakness in the application's input sanitization mechanisms where the XSS protection is bypassed when both messageHTML and messagePlainText parameters are submitted within the same HTTP request. The flaw exists in the message handling and rendering components of the email server application, which processes and stores user-supplied content that can later be executed in the context of other users' browsers.
The technical implementation of this vulnerability stems from improper validation and sanitization of user input within the email composition interface. When an attacker crafts a malicious payload and submits it as both HTML and plain text content simultaneously, the application's security controls fail to properly sanitize the input before storing it in the database. This creates a persistent XSS vector where the malicious code is stored and subsequently executed whenever other users view the affected email messages. The vulnerability is classified under CWE-79 as Improper Neutralization of Input During Web Page Generation, which represents one of the most prevalent and dangerous web application security flaws.
From an operational perspective, this stored XSS vulnerability poses significant risks to organizations using SmarterMail as their email infrastructure. Attackers can leverage this flaw to execute malicious scripts in the context of authenticated users' browsers, potentially leading to session hijacking, credential theft, or privilege escalation within the email system. The impact extends beyond simple data theft as attackers can manipulate the email interface to redirect users to malicious sites, inject malicious advertisements, or even modify email content to facilitate further attacks. The persistence of stored XSS means that the vulnerability remains active until the malicious content is removed from the system, making it particularly dangerous for organizations with high email traffic volumes.
The exploitation of this vulnerability aligns with ATT&CK technique T1566.001 for Phishing and T1584.002 for Compromise of Infrastructure, as attackers can use the stored XSS to compromise user accounts and establish persistent access to email systems. Organizations utilizing SmarterMail should immediately implement mitigations including input validation, output encoding, and proper content sanitization mechanisms. The recommended approach involves updating to the patched version 8747 or later, implementing additional input validation layers, and conducting thorough security assessments of email content handling processes. Security teams should also consider implementing web application firewalls and monitoring for suspicious input patterns that may indicate attempts to exploit this vulnerability. Additionally, user education and awareness programs should be enhanced to recognize potential phishing attempts that may leverage this XSS vector for credential theft or system compromise.