An Access of Uninitialized Pointer vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved with BGP sharding configured allows an attacker triggering indirect next-hop updates, along with timing outside the attackers control, to cause rpd to crash and restart, leading to a Denial of Service (DoS).
With BGP sharding enabled, triggering route resolution of an indirect next-hop (e.g., an IGP route change over which a BGP route gets resolved), may cause rpd to crash and restart. An attacker causing continuous IGP route churn, resulting in repeated route re-resolution, will increase the likelihood of triggering this issue, leading to a potentially extended DoS condition.
This issue affects:
Junos OS:
Junos OS Evolved:
Versions before Junos OS 21.3R1 and Junos OS Evolved 21.3R1-EVO are unaffected by this issue.
The product accesses or uses a pointer that has not been initialized.
If the pointer contains an uninitialized value, then the value might not point to a valid memory location. This could cause the product to read from or write to unexpected memory locations, leading to a denial of service. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked. If an attacker can influence the portion of uninitialized memory that is contained in the pointer, this weakness could be leveraged to execute code or perform other attacks. Depending on memory layout, associated memory management behaviors, and product operation, the attacker might be able to influence the contents of the uninitialized pointer, thus gaining more fine-grained control of the memory location to be accessed.