An Improper Release of Memory Before Removing Last Reference vulnerability in Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows a local, low privileged attacker to cause an FPC crash, leading to Denial of Service (DoS).
On all Junos MX Series with MPC1 - MPC9, LC480, LC2101, MX10003, and MX80, when Connectivity-Fault-Management (CFM) is enabled in a VPLS scenario, and a specific LDP related command is run, an FPC will crash and reboot. Continued execution of this specific LDP command can lead to sustained Denial of Service condition.
This issue affects:
Juniper Networks Junos OS on MX Series:
- All versions prior to 20.4R3-S7;
- 21.1 versions prior to 21.1R3-S5;
- 21.2 versions prior to 21.2R3-S4;
- 21.3 versions prior to 21.3R3-S4;
- 21.4 versions prior to 21.4R3-S3;
- 22.1 versions prior to 22.1R3-S1;
- 22.2 versions prior to 22.2R2-S1, 22.2R3;
- 22.3 versions prior to 22.3R1-S2, 22.3R2.
Weakness
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos | Juniper | * | 20.4 (excluding) |
| Junos | Juniper | 20.4 (including) | 20.4 (including) |
| Junos | Juniper | 20.4-r1 (including) | 20.4-r1 (including) |
| Junos | Juniper | 20.4-r1-s1 (including) | 20.4-r1-s1 (including) |
| Junos | Juniper | 20.4-r2 (including) | 20.4-r2 (including) |
| Junos | Juniper | 20.4-r2-s1 (including) | 20.4-r2-s1 (including) |
| Junos | Juniper | 20.4-r2-s2 (including) | 20.4-r2-s2 (including) |
| Junos | Juniper | 20.4-r3 (including) | 20.4-r3 (including) |
| Junos | Juniper | 20.4-r3-s1 (including) | 20.4-r3-s1 (including) |
| Junos | Juniper | 20.4-r3-s2 (including) | 20.4-r3-s2 (including) |
| Junos | Juniper | 20.4-r3-s3 (including) | 20.4-r3-s3 (including) |
| Junos | Juniper | 20.4-r3-s4 (including) | 20.4-r3-s4 (including) |
| Junos | Juniper | 20.4-r3-s5 (including) | 20.4-r3-s5 (including) |
| Junos | Juniper | 20.4-r3-s6 (including) | 20.4-r3-s6 (including) |
| Junos | Juniper | 21.1 (including) | 21.1 (including) |
| Junos | Juniper | 21.1-r1 (including) | 21.1-r1 (including) |
| Junos | Juniper | 21.1-r1-s1 (including) | 21.1-r1-s1 (including) |
| Junos | Juniper | 21.1-r2 (including) | 21.1-r2 (including) |
| Junos | Juniper | 21.1-r2-s1 (including) | 21.1-r2-s1 (including) |
| Junos | Juniper | 21.1-r2-s2 (including) | 21.1-r2-s2 (including) |
| Junos | Juniper | 21.1-r3 (including) | 21.1-r3 (including) |
| Junos | Juniper | 21.1-r3-s1 (including) | 21.1-r3-s1 (including) |
| Junos | Juniper | 21.1-r3-s2 (including) | 21.1-r3-s2 (including) |
| Junos | Juniper | 21.1-r3-s3 (including) | 21.1-r3-s3 (including) |
| Junos | Juniper | 21.1-r3-s4 (including) | 21.1-r3-s4 (including) |
| Junos | Juniper | 21.2 (including) | 21.2 (including) |
| Junos | Juniper | 21.2-r1 (including) | 21.2-r1 (including) |
| Junos | Juniper | 21.2-r1-s1 (including) | 21.2-r1-s1 (including) |
| Junos | Juniper | 21.2-r1-s2 (including) | 21.2-r1-s2 (including) |
| Junos | Juniper | 21.2-r2 (including) | 21.2-r2 (including) |
| Junos | Juniper | 21.2-r2-s1 (including) | 21.2-r2-s1 (including) |
| Junos | Juniper | 21.2-r2-s2 (including) | 21.2-r2-s2 (including) |
| Junos | Juniper | 21.2-r3 (including) | 21.2-r3 (including) |
| Junos | Juniper | 21.2-r3-s1 (including) | 21.2-r3-s1 (including) |
| Junos | Juniper | 21.2-r3-s2 (including) | 21.2-r3-s2 (including) |
| Junos | Juniper | 21.2-r3-s3 (including) | 21.2-r3-s3 (including) |
| Junos | Juniper | 21.3 (including) | 21.3 (including) |
| Junos | Juniper | 21.3-r1 (including) | 21.3-r1 (including) |
| Junos | Juniper | 21.3-r1-s1 (including) | 21.3-r1-s1 (including) |
| Junos | Juniper | 21.3-r1-s2 (including) | 21.3-r1-s2 (including) |
| Junos | Juniper | 21.3-r2 (including) | 21.3-r2 (including) |
| Junos | Juniper | 21.3-r2-s1 (including) | 21.3-r2-s1 (including) |
| Junos | Juniper | 21.3-r2-s2 (including) | 21.3-r2-s2 (including) |
| Junos | Juniper | 21.3-r3 (including) | 21.3-r3 (including) |
| Junos | Juniper | 21.3-r3-s1 (including) | 21.3-r3-s1 (including) |
| Junos | Juniper | 21.3-r3-s2 (including) | 21.3-r3-s2 (including) |
| Junos | Juniper | 21.3-r3-s3 (including) | 21.3-r3-s3 (including) |
| Junos | Juniper | 21.4 (including) | 21.4 (including) |
| Junos | Juniper | 21.4-r1 (including) | 21.4-r1 (including) |
| Junos | Juniper | 21.4-r1-s1 (including) | 21.4-r1-s1 (including) |
| Junos | Juniper | 21.4-r1-s2 (including) | 21.4-r1-s2 (including) |
| Junos | Juniper | 21.4-r2 (including) | 21.4-r2 (including) |
| Junos | Juniper | 21.4-r2-s1 (including) | 21.4-r2-s1 (including) |
| Junos | Juniper | 21.4-r2-s2 (including) | 21.4-r2-s2 (including) |
| Junos | Juniper | 22.1-r1 (including) | 22.1-r1 (including) |
| Junos | Juniper | 22.1-r1-s1 (including) | 22.1-r1-s1 (including) |
| Junos | Juniper | 22.1-r1-s2 (including) | 22.1-r1-s2 (including) |
| Junos | Juniper | 22.1-r2 (including) | 22.1-r2 (including) |
| Junos | Juniper | 22.1-r2-s1 (including) | 22.1-r2-s1 (including) |
| Junos | Juniper | 22.1-r2-s2 (including) | 22.1-r2-s2 (including) |
| Junos | Juniper | 22.1-r3 (including) | 22.1-r3 (including) |
| Junos | Juniper | 22.2 (including) | 22.2 (including) |
| Junos | Juniper | 22.2-r1 (including) | 22.2-r1 (including) |
| Junos | Juniper | 22.2-r1-s1 (including) | 22.2-r1-s1 (including) |
| Junos | Juniper | 22.2-r1-s2 (including) | 22.2-r1-s2 (including) |
| Junos | Juniper | 22.2-r2 (including) | 22.2-r2 (including) |
| Junos | Juniper | 22.3-r1 (including) | 22.3-r1 (including) |
| Junos | Juniper | 22.3-r1-s1 (including) | 22.3-r1-s1 (including) |
| Junos | Juniper | 22.3-r1-s2 (including) | 22.3-r1-s2 (including) |
| Junos | Juniper | 22.3-r2 (including) | 22.3-r2 (including) |
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.