CVE-2020-11078 in httplib2
Summary
by MITRE
In httplib2 before version 0.18.0, an attacker controlling unescaped part of uri for `httplib2.Http.request()` could change request headers and body, send additional hidden requests to same server. This vulnerability impacts software that uses httplib2 with uri constructed by string concatenation, as opposed to proper urllib building with escaping. This has been fixed in 0.18.0.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/18/2020
The vulnerability identified as CVE-2020-11078 represents a critical security flaw in the httplib2 library version 0.18.0 and earlier, where improper handling of URI components creates opportunities for header injection and additional request manipulation. This issue specifically affects applications that construct URI strings through simple concatenation rather than utilizing proper URL building functions with appropriate escaping mechanisms. The flaw stems from the library's insufficient validation of URI components, particularly those that remain unescaped during request processing.
The technical implementation of this vulnerability occurs when an attacker can influence parts of a URI that are not properly escaped before being processed by the httplib2.Http.request() method. When URI components such as paths, query parameters, or fragments contain unescaped special characters, the library fails to properly separate these components from the actual request headers and body. This allows an attacker to inject malicious headers or modify the request structure in ways that can bypass security controls and potentially enable unauthorized actions.
The operational impact of this vulnerability extends beyond simple header injection, as it enables attackers to send additional hidden requests to the same server. This creates opportunities for various attack vectors including but not limited to cache poisoning, session manipulation, and data exfiltration. The vulnerability is particularly dangerous because it can be exploited in applications that rely on string concatenation for URI construction rather than proper URL building libraries that automatically handle escaping. This pattern is common in legacy applications or those that have not been updated to follow modern security practices.
Software that uses httplib2 with improperly constructed URIs becomes vulnerable to this attack, especially in environments where user input or external data influences URI construction. The attack can be particularly effective in applications that process user-provided URLs or URLs constructed from multiple data sources without proper sanitization and escaping. This vulnerability affects the integrity of HTTP communications and can lead to unauthorized access to resources or manipulation of application behavior.
Mitigation strategies for this vulnerability require immediate library version updates to 0.18.0 or later where the fix has been implemented. Organizations should also review their codebases for improper URI construction patterns and implement proper URL building functions that automatically handle escaping. The fix addresses the core issue by ensuring that URI components are properly separated and validated before being processed by the HTTP request methods, preventing the injection of malicious content into request headers or bodies. Security teams should also consider implementing input validation and sanitization measures for any URI construction processes and conduct thorough code reviews to identify similar patterns that may exist in other libraries or custom implementations.
This vulnerability aligns with CWE-113 (Improper Neutralization of CRLF Characters in HTTP Headers) and CWE-94 (Improper Control of Generation of Code) categories, representing a combination of header injection and code generation flaws. From an ATT&CK perspective, this vulnerability maps to T1071.004 (Application Layer Protocol: DNS) and T1566 (Phishing) as it can enable attackers to manipulate HTTP communications and potentially redirect traffic. The vulnerability demonstrates the importance of proper input validation and escaping in network communication libraries and highlights the need for security-conscious development practices in handling URI components.