CVE-2017-9265 in vSwitch
Summary
by MITRE
In Open vSwitch (OvS) v2.7.0, there is a buffer over-read while parsing the group mod OpenFlow message sent from the controller in `lib/ofp-util.c` in the function `ofputil_pull_ofp15_group_mod`.
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Analysis
by VulDB Data Team • 12/07/2022
The vulnerability identified as CVE-2017-9265 represents a critical buffer over-read condition within Open vSwitch version 2.7.0 that arises during the processing of OpenFlow group modification messages. This flaw exists in the `lib/ofp-util.c` source file within the `ofputil_pull_ofp15_group_mod` function, where the software fails to properly validate input data structures before attempting to read from memory regions that may exceed allocated buffer boundaries. The issue stems from insufficient bounds checking during the parsing of group mod messages that are sent from OpenFlow controllers to the switch implementation, creating a potential pathway for malicious input to trigger unauthorized memory access patterns.
The technical exploitation of this vulnerability occurs when an attacker crafts a specially formatted OpenFlow group mod message that contains malformed or oversized data fields. During message parsing, the function attempts to read beyond the intended buffer limits without proper validation of the message length or field boundaries, leading to a buffer over-read condition. This memory corruption can result in unpredictable behavior including system crashes, data leakage, or potentially remote code execution depending on the specific memory layout and the attacker's ability to control the read operations. The vulnerability specifically affects the OpenFlow protocol version 1.5 implementation within the OvS codebase, making it particularly relevant for environments that utilize modern OpenFlow features.
The operational impact of CVE-2017-9265 extends beyond simple system instability to encompass potential security breaches in virtualized networking environments that rely on Open vSwitch for network virtualization. Network administrators and security professionals must recognize that this vulnerability can be exploited by attackers who gain access to the OpenFlow control channel, potentially allowing them to compromise the integrity of virtualized network infrastructure. The vulnerability aligns with CWE-125, which categorizes buffer over-read conditions as a fundamental memory safety issue, and represents a significant concern for organizations using OvS in cloud computing environments, software-defined networking deployments, and network virtualization platforms where the controller and switch components communicate over OpenFlow protocols.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and implementation of defensive programming practices. Organizations should prioritize upgrading to Open vSwitch versions that contain patches addressing this specific buffer over-read condition, typically found in versions subsequent to 2.7.0. Additionally, network administrators should implement strict access controls and authentication mechanisms around OpenFlow control channels to limit potential exploitation vectors. The vulnerability demonstrates the importance of input validation and bounds checking in network protocol implementations, aligning with ATT&CK technique T1059 for executing commands through network protocols and T1133 for persistence via network infrastructure. Security monitoring should include detection of anomalous OpenFlow message patterns that might indicate exploitation attempts, particularly focusing on group mod message structures that exceed expected parameter boundaries.