CVE-2007-5712 in Django
Summary
by MITRE
The internationalization (i18n) framework in Django 0.91, 0.95, 0.95.1, and 0.96, and as used in other products such as PyLucid, when the USE_I18N option and the i18n component are enabled, allows remote attackers to cause a denial of service (memory consumption) via many HTTP requests with large Accept-Language headers.
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Analysis
by VulDB Data Team • 07/29/2019
The vulnerability described in CVE-2007-5712 represents a significant denial of service weakness within Django's internationalization framework that affects multiple versions including 0.91, 0.95, 0.95.1, and 0.96. This flaw specifically manifests when the USE_I18N option is enabled alongside the i18n component, creating a condition where remote attackers can exploit the system's handling of Accept-Language headers to consume excessive memory resources. The issue stems from the framework's inadequate processing of malformed or excessively large Accept-Language header values, which can cause the application to allocate memory proportional to the header size without proper bounds checking or rate limiting mechanisms.
The technical exploitation of this vulnerability involves sending multiple HTTP requests containing large Accept-Language headers to the affected Django application. Each request triggers the i18n framework to parse and process these headers, leading to progressive memory allocation that can eventually exhaust available system resources. This behavior constitutes a classic resource exhaustion attack pattern that aligns with attack techniques categorized under the MITRE ATT&CK framework's resource exhaustion tactics. The vulnerability is particularly concerning because it requires no authentication or specialized privileges to exploit, making it accessible to any remote attacker who can send HTTP requests to the target system.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the overall stability and availability of applications running on affected Django versions. When exploited successfully, the memory consumption grows linearly with each malicious request, potentially leading to application crashes, system slowdowns, or complete service unavailability. This makes the vulnerability particularly dangerous in production environments where application availability is critical, as it can be used to effectively shut down services without requiring sophisticated attack vectors or access to system resources. The vulnerability affects not only Django directly but also other products that utilize Django's i18n framework, such as PyLucid, amplifying its potential impact across the broader web application ecosystem.
Organizations affected by this vulnerability should implement immediate mitigations including rate limiting of HTTP requests, implementing size restrictions on Accept-Language headers, and upgrading to patched versions of Django where available. The vulnerability maps to CWE-400, which specifically addresses unchecked resource allocation, and represents a clear example of how internationalization features can introduce security weaknesses when not properly implemented with resource management considerations. System administrators should also consider implementing monitoring solutions to detect unusual memory consumption patterns that might indicate exploitation attempts. Additionally, the issue highlights the importance of proper input validation and bounds checking in web application frameworks, particularly in components that process user-supplied data such as HTTP headers, which aligns with the broader security principles outlined in the OWASP Top Ten and other industry security standards.