Description

A Heap-based Buffer Overflow vulnerability in the SVR component of Juniper Networks Junos OS on SRX Series allows an unauthenticated network attacker to cause a denial of service and potentially compromise confidentiality and integrity via malformed IPv4 packets reaching an interface configured for Secure Vector Routing.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-14T17:17:47.877Z",
  "pubdate": "2026-10-14T17:17:47.877Z",
  "executiveSummary": "A heap-based buffer overflow vulnerability exists within the Secure Vector Routing (SVR) component of Juniper Networks Junos OS on SRX Series devices. This vulnerability allows an unauthenticated, remote attacker to trigger a memory corruption condition by sending specifically crafted, malformed IPv4 packets to an interface configured with SVR.\nThe successful exploitation of this flaw can lead to a Denial of Service (DoS) state, where the device becomes unresponsive or crashes due to unexpected process termination. Beyond service disruption, the heap corruption may permit arbitrary code execution, potentially granting an attacker the ability to compromise the confidentiality and integrity of the affected system. Given the unauthenticated nature of the attack, the vulnerability poses a significant risk to network infrastructure. Exploitation requires the target interface to have the SVR functionality enabled, but does not require prior knowledge of internal system states or credentials.",
  "technicalDetails": "The vulnerability resides within the SVR process responsible for handling incoming IPv4 traffic on SRX Series platforms. A heap-based buffer overflow occurs when the SVR component fails to properly validate the length or structure of incoming IPv4 packets before copying them into a heap-allocated buffer. When a malformed IPv4 packet is received, the SVR parsing logic miscalculates the required buffer size or fails to enforce boundary checks during the packet-copying operation.\nThe attack flow initiates when an unauthenticated attacker transmits a malformed IPv4 packet targeted at an interface where SVR is actively configured. As the SVR component processes the incoming data, the vulnerable function attempts to write the packet payload into a memory buffer located on the heap. Because of the missing bounds checking, the packet data overflows the allocated heap chunk, overwriting adjacent memory structures. This memory corruption can be leveraged to corrupt function pointers, object metadata, or return addresses stored on the heap.\nThe primary impact of this heap overflow is process-level instability. By overwriting critical control structures, an attacker can trigger an exception that leads to a process crash, effectively causing a Denial of Service. In more sophisticated scenarios, if the attacker can precisely control the heap layout—often referred to as heap grooming or heap spraying—they may overwrite specific data objects to achieve arbitrary code execution. Successful execution under these conditions grants the attacker the same privilege level as the SVR process, which generally runs with high enough permissions to interact with sensitive networking subsystems, thereby compromising the overall integrity and confidentiality of the device.\nThe vulnerability is limited to interfaces configured for Secure Vector Routing. Because the SVR component is involved in network-level packet handling, the attack surface is exposed directly to any network segments that can reach the device interface. No authentication or elevated user privileges are required to reach the vulnerable code path, as the packet processing occurs early in the protocol stack before session-based authentication mechanisms are typically invoked."
}