CVE-2024-30401 in Junos OS
Summary
by MITRE • 04/12/2024
An Out-of-bounds Read vulnerability in the advanced forwarding management process aftman of Juniper Networks Junos OS on MX Series with MPC10E, MPC11, MX10K-LC9600 line cards, MX304, and EX9200-15C, may allow an attacker to exploit a stack-based buffer overflow, leading to a reboot of the FPC.
Through code review, it was determined that the interface definition code for aftman could read beyond a buffer boundary, leading to a stack-based buffer overflow. This issue affects Junos OS on MX Series and EX9200-15C:
* from 21.2 before 21.2R3-S1, * from 21.4 before 21.4R3, * from 22.1 before 22.1R2, * from 22.2 before 22.2R2;
This issue does not affect:
* versions of Junos OS prior to 20.3R1; * any version of Junos OS 20.4.
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Analysis
by VulDB Data Team • 01/23/2026
The vulnerability identified as CVE-2024-30401 represents a critical out-of-bounds read condition within the advanced forwarding management process known as aftman in Juniper Networks Junos OS implementations. This flaw specifically impacts hardware platforms including MX Series routers with MPC10E, MPC11, MX10K-LC9600 line cards, MX304 devices, and EX9200-15C switches. The security issue stems from improper boundary checking in the interface definition code handling within the aftman process, creating a stack-based buffer overflow scenario that can be exploited by remote attackers to cause system disruptions.
The technical exploitation of this vulnerability occurs through a stack-based buffer overflow condition that arises when the aftman process attempts to read beyond allocated memory boundaries during interface definition processing. This type of flaw falls under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read vulnerabilities. The buffer overflow condition manifests when the software processes interface definitions without adequate validation of input boundaries, allowing malicious data to overwrite adjacent memory locations on the stack. The operational impact of this vulnerability extends beyond simple memory corruption to include system stability issues, as evidenced by the potential for complete device reboots of the Flexible PIC Concentrator (FPC) components.
The attack surface for this vulnerability encompasses network administrators and malicious actors who can potentially leverage this flaw through network-based attacks targeting the affected Junos OS versions. The specific affected versions include releases from 21.2 before 21.2R3-S1, 21.4 before 21.4R3, 22.1 before 22.1R2, and 22.2 before 22.2R2, while older versions prior to 20.3R1 and the 20.4 release series remain unaffected. This particular vulnerability aligns with ATT&CK technique T1499.002, which covers network denial of service attacks through exploitation of system resources, and represents a significant threat to network infrastructure reliability. The impact of such a vulnerability extends to network availability and operational continuity, as unauthorized rebooting of FPC components can result in service disruption and potential cascading failures in network operations.
The remediation strategy for this vulnerability requires immediate deployment of patched firmware versions for all affected Junos OS releases, with particular attention to the specific version ranges mentioned in the advisory. Network security teams should prioritize patching operations across all affected MX Series and EX9200-15C devices in their infrastructure, implementing a phased approach that minimizes operational disruption while ensuring complete vulnerability remediation. Organizations should also consider implementing network segmentation and access controls to limit potential attack vectors targeting these specific devices, while monitoring network traffic for anomalous patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and boundary checking in network infrastructure software, particularly in critical forwarding processes that handle interface definitions and network configuration data.