A Missing Release of Memory after Effective Lifetime vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS).
In a subscriber management scenario, login/logout activity triggers a memory leak, and the leaked memory gradually increments and eventually results in a crash.
user@host> show chassis fpc
Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%)
Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer
2 Online 36 10 0 9 8 9 32768 26 0
This issue affects Junos OS on MX Series:
- All versions before 21.2R3-S9
- from 21.4 before 21.4R3-S10
- from 22.2 before 22.2R3-S6
- from 22.4 before 22.4R3-S5
- from 23.2 before 23.2R2-S3
- from 23.4 before 23.4R2-S3
- from 24.2 before 24.2R2.
Weakness
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
Potential Mitigations
- Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
- For example, glibc in Linux provides protection against free of invalid pointers.
- When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
- To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.
References