CVE-2018-18628 in Pippo
Summary
by MITRE
An issue was discovered in Pippo 1.11.0. The function SerializationSessionDataTranscoder.decode() calls ObjectInputStream.readObject() to deserialize a SessionData object without checking the object types. An attacker can create a malicious object, base64 encode it, and place it in the PIPPO_SESSION field of a cookie. Sending this cookie may lead to remote code execution.
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Analysis
by VulDB Data Team • 05/30/2023
The vulnerability identified as CVE-2018-18628 affects Pippo version 1.11.0 and represents a critical deserialization flaw that can lead to remote code execution. This issue resides within the SerializationSessionDataTranscoder.decode() function which processes session data objects through the ObjectInputStream.readObject() method without proper type validation. The flaw demonstrates a classic insecure deserialization pattern where the application accepts serialized data from untrusted sources and directly deserializes it without sanitization or type checking mechanisms. This vulnerability is particularly dangerous because it allows attackers to craft malicious serialized objects that can execute arbitrary code when processed by the vulnerable application.
The technical exploitation of this vulnerability follows a well-established attack pattern that aligns with CWE-502, which specifically addresses deserialization of untrusted data. Attackers can create malicious Java serialized objects containing malicious payload code, base64 encode them, and inject them into the PIPPO_SESSION cookie field. When the application processes this cookie during subsequent requests, the deserialization process triggers the execution of the attacker's payload within the context of the web application. The attack leverages the Java serialization mechanism's inherent risks, where the readObject() method can invoke any constructor or method within the deserialized object hierarchy, making it a prime target for remote code execution attacks.
The operational impact of CVE-2018-18628 extends beyond simple privilege escalation as it provides attackers with complete control over the affected application server. This vulnerability can be exploited through simple HTTP requests containing the malicious cookie, making it particularly dangerous for web applications that store session data in cookies. The attack surface is broad since any application using Pippo 1.11.0 and handling session data through the vulnerable deserialization path becomes susceptible. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under the T1203 category for legitimate credential access and T1059 for command and script interpreter, as attackers can execute arbitrary commands through the deserialization process.
Mitigation strategies for this vulnerability must address the core deserialization flaw through multiple defensive layers. The primary recommendation involves implementing proper type checking and validation during the deserialization process, ensuring that only expected object types are accepted. Organizations should consider replacing the vulnerable ObjectInputStream.readObject() calls with safer alternatives such as using custom deserialization logic that validates object types or implementing a whitelist of allowed classes. Additionally, the application should employ secure session management practices including the use of signed or encrypted session tokens, proper input validation, and the implementation of a robust security framework that prevents deserialization of untrusted data. The vulnerability also highlights the importance of keeping dependencies updated and following secure coding practices that align with OWASP secure coding guidelines for preventing deserialization attacks.