CVE-2022-22233 in Junos OS
Summary
by MITRE • 10/18/2022
An Unchecked Return Value to NULL Pointer Dereference vulnerability in Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a locally authenticated attacker with low privileges to cause a Denial of Service (DoS). In Segment Routing (SR) to Label Distribution Protocol (LDP) interworking scenario, configured with Segment Routing Mapping Server (SRMS) at any node, when an Area Border Router (ABR) leaks the SRMS entries having "S" flag set from IS-IS Level 2 to Level 1, an rpd core might be observed when a specific low privileged CLI command is issued. This issue affects: Juniper Networks Junos OS 21.4 versions prior to 21.4R1-S2, 21.4R2-S1, 21.4R3; 22.1 versions prior to 22.1R2. Juniper Networks Junos OS Evolved 21.4-EVO versions prior to 21.4R1-S2-EVO, 21.4R2-S1-EVO, 21.4R3-EVO; 22.1-EVO versions prior to 22.1R2-EVO. This issue does not affect: Juniper Networks Junos OS versions prior to 21.4R1. Juniper Networks Junos OS Evolved versions prior to 21.4R1-EVO.
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Analysis
by VulDB Data Team • 10/18/2022
The vulnerability described in CVE-2022-22233 represents a critical unchecked return value that leads to a NULL pointer dereference within the Routing Protocol Daemon (rpd) component of Juniper Networks Junos OS and Junos OS Evolved platforms. This issue specifically manifests in Segment Routing (SR) environments where the Label Distribution Protocol (LDP) interworks with Segment Routing Mapping Server (SRMS) functionality. The flaw occurs when an Area Border Router (ABR) performs route leaking operations from IS-IS Level 2 to Level 1, particularly when SRMS entries contain the "S" flag set, creating a scenario where the rpd process can crash and generate a core dump. The vulnerability is classified under CWE-476 as NULL Pointer Dereference, which is a common class of software defects that can lead to system instability and denial of service conditions. This vulnerability affects a specific subset of Junos OS versions, including various 21.4 and 22.1 releases, with corresponding Evolved versions, while excluding earlier releases that were not impacted by this particular code path.
The technical exploitation of this vulnerability requires a locally authenticated attacker with low privileges who can execute specific CLI commands within the affected routing environment. The operational impact is significant as it results in a Denial of Service condition that can disrupt network routing operations and potentially affect network availability. The attack vector is limited to local access within the routing domain, making it less likely to be exploited remotely, but still represents a serious threat to network stability. When triggered, the vulnerability causes the rpd process to crash, which can lead to routing table inconsistencies, potential network partitions, and loss of connectivity for routing functions within the affected network segments. The specific conditions required for exploitation involve the configuration of Segment Routing Mapping Server functionality and the particular route leaking behavior between IS-IS levels, making this vulnerability highly contextual and dependent on specific network topologies and routing configurations.
From a security operations perspective, this vulnerability aligns with ATT&CK technique T1499.004 for Network Denial of Service, as it specifically enables an attacker to cause service disruption through routing protocol instability. The vulnerability demonstrates a classic example of poor error handling in network infrastructure software, where the return value from a function call is not properly validated before being used in subsequent operations. This represents a fundamental flaw in defensive programming practices where the code assumes certain conditions will always be met without proper validation. Organizations affected by this vulnerability should immediately implement mitigation strategies including applying the relevant security patches provided by Juniper Networks, which address the specific code path that leads to the NULL pointer dereference. Network administrators should also consider implementing monitoring for rpd process crashes and core dump generation as early warning indicators of potential exploitation attempts. The vulnerability affects both traditional Junos OS and the newer Junos OS Evolved platform, indicating that the underlying code issue is present in the core routing daemon implementation across Juniper's product lines. Given the nature of routing protocols and their critical role in network infrastructure, this vulnerability represents a significant risk to network availability and requires immediate attention from security teams responsible for maintaining routing infrastructure.