CVE-2018-1000089 in django-anymail
Summary
by MITRE
Anymail django-anymail version version 0.2 through 1.3 contains a CWE-532, CWE-209 vulnerability in WEBHOOK_AUTHORIZATION setting value that can result in An attacker with access to error logs could fabricate email tracking events. This attack appear to be exploitable via If you have exposed your Django error reports, an attacker could discover your ANYMAIL_WEBHOOK setting and use this to post fabricated or malicious Anymail tracking/inbound events to your app. This vulnerability appears to have been fixed in v1.4.
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Analysis
by VulDB Data Team • 02/21/2023
The vulnerability described in CVE-2018-1000089 affects the django-anymail package, a popular Django email integration library that provides support for various email service providers including SendGrid, Mailgun, and Amazon SES. This issue specifically targets the WEBHOOK_AUTHORIZATION setting implementation within the Anymail framework, creating a significant security risk for applications that process email tracking events and inbound messages through webhook endpoints. The vulnerability exists in versions 0.2 through 1.3 of the package and represents a classic case of information exposure through error handling mechanisms, classified under CWE-532 (Information Exposure Through Log Data) and CWE-209 (Information Exposure Through Error Message).
The technical flaw stems from how the Anymail package handles webhook authorization tokens when errors occur during processing. When Django error reporting is enabled and exposed to attackers, the system inadvertently reveals the WEBHOOK_AUTHORIZATION setting value through error messages or stack traces. This exposure allows malicious actors to extract the authorization token used for validating webhook requests from email service providers. The vulnerability operates under the principle that sensitive configuration values should never be exposed through error handling mechanisms, as demonstrated by the ATT&CK technique T1562.001 (TTP: Disable or Modify Tools) and T1070.004 (TTP: Indicator Removal on Host). Attackers can then leverage this extracted token to forge webhook requests that appear legitimate to the Django application, enabling them to manipulate email tracking events and potentially inject malicious content.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a pathway for attackers to manipulate email processing workflows within vulnerable applications. An attacker who gains access to error logs can fabricate email tracking events such as delivery confirmations, bounces, or click tracking, potentially disrupting email marketing campaigns or bypassing security controls. The vulnerability also enables unauthorized inbound email processing, allowing attackers to send malicious content through email webhook endpoints that the application would normally trust. This represents a critical compromise of the application's email security posture and can lead to data manipulation, service disruption, and potential escalation to other system components. The attack vector requires only access to exposed error reports, making it particularly dangerous for applications that do not properly sanitize error output or implement comprehensive logging controls.
The fix implemented in version 1.4 addresses this vulnerability by ensuring that the WEBHOOK_AUTHORIZATION setting values are not exposed through error messages or stack traces. This update aligns with security best practices outlined in the OWASP Top Ten 2017 and the NIST Cybersecurity Framework, specifically addressing the principle of least privilege and secure error handling. Organizations should immediately upgrade to version 1.4 or later to remediate this vulnerability, while also implementing comprehensive logging controls to prevent sensitive configuration data from appearing in error reports. Additional mitigations include disabling or restricting access to error reporting endpoints, implementing proper input validation for webhook requests, and ensuring that authorization tokens are stored securely using environment variables rather than hardcoded values. The vulnerability serves as a reminder of the critical importance of secure configuration management and proper error handling in web applications, particularly those handling sensitive communication data through email service integrations.