CVE-2023-41331 in SOFARPC
Summary
by MITRE • 09/12/2023
SOFARPC is a Java RPC framework. Versions prior to 5.11.0 are vulnerable to remote command execution. Through a carefully crafted payload, an attacker can achieve JNDI injection or system command execution. In the default configuration of the SOFARPC framework, a blacklist is used to filter out dangerous classes encountered during the deserialization process. However, the blacklist is not comprehensive, and an actor can exploit certain native JDK classes and common third-party packages to construct gadget chains capable of achieving JNDI injection or system command execution attacks. Version 5.11.0 contains a fix for this issue. As a workaround, users can add `-Drpc_serialize_blacklist_override=javax.sound.sampled.AudioFileFormat` to the blacklist.
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Analysis
by VulDB Data Team • 09/13/2023
The vulnerability CVE-2023-41331 affects the SOFARPC Java RPC framework, a widely used enterprise-level communication framework that facilitates remote procedure calls between distributed systems. This vulnerability represents a critical security flaw that allows remote attackers to execute arbitrary commands on affected systems, potentially leading to complete system compromise. The issue stems from insufficient input validation and insecure deserialization practices within the framework's serialization mechanism, creating an attack surface that can be exploited without authentication. The vulnerability impacts all versions prior to 5.11.0, making it particularly concerning for organizations that may have legacy deployments or delayed upgrade cycles.
The technical flaw manifests through the framework's deserialization process where a comprehensive blacklist mechanism is supposed to prevent dangerous class loading operations. However, this blacklist implementation contains significant gaps that allow attackers to leverage native JDK classes and commonly used third-party libraries to construct gadget chains for exploitation. The attack vector specifically targets JNDI injection capabilities, which can be leveraged to load malicious classes from remote servers, effectively enabling remote code execution. This type of vulnerability aligns with CWE-502, which describes "Deserialization of Untrusted Data" as a common weakness that leads to remote code execution through gadget chain construction. The exploitation technique involves crafting malicious payloads that bypass the existing blacklist by using alternative class paths that are not properly filtered.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential lateral movement within enterprise networks. Attackers can leverage this vulnerability to establish persistent backdoors, exfiltrate sensitive data, or use the compromised systems as launch points for further attacks. The default configuration of SOFARPC makes this vulnerability particularly dangerous as it does not require any special privileges or authentication to exploit, allowing attackers to target systems directly from the internet. Organizations using SOFARPC frameworks in production environments face significant risk of data breaches, service disruption, and regulatory compliance violations if this vulnerability remains unpatched. The attack can be particularly devastating in cloud environments where SOFARPC is often used for microservices communication, potentially enabling attackers to compromise entire distributed application architectures.
The recommended mitigation strategy involves immediate upgrading to SOFARPC version 5.11.0 or later, which includes comprehensive fixes for the deserialization vulnerability. Organizations unable to perform immediate upgrades should implement the temporary workaround of adding the JVM parameter -Drpc_serialize_blacklist_override=javax.sound.sampled.AudioFileFormat to their application startup configurations. This approach extends the existing blacklist to include the problematic AudioFileFormat class that can be used in exploitation attempts. Additional security measures should include network segmentation to limit access to SOFARPC endpoints, monitoring for suspicious deserialization activities, and implementing application firewalls to detect and block malicious payloads. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for remote code execution and T1566 for initial access through application vulnerabilities. Organizations should also consider implementing runtime protection mechanisms and regular security assessments to identify similar vulnerabilities in other components of their software stack.