Vulnerabilities > CVE-2021-0234 - Improper Initialization vulnerability in Juniper Junos
Summary
Due to an improper Initialization vulnerability on Juniper Networks Junos OS QFX5100-96S devices with QFX 5e Series image installed, ddos-protection configuration changes will not take effect beyond the default DDoS (Distributed Denial of Service) settings when configured from the CLI. The DDoS protection (jddosd) daemon allows the device to continue to function while protecting the packet forwarding engine (PFE) during the DDoS attack. When this issue occurs, the default DDoS settings within the PFE apply, as CPU bound packets will be throttled and dropped in the PFE when the limits are exceeded. To check if the device has this issue, the administrator can execute the following command to monitor the status of DDoS protection: user@device> show ddos-protection protocols error: the ddos-protection subsystem is not running This issue affects only QFX5100-96S devices. No other products or platforms are affected by this issue. This issue affects: Juniper Networks Junos OS on QFX5100-96S: 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R3-S4; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R3-S3; 18.3 versions prior to 18.3R3-S2; 18.4 versions prior to 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R3, 19.1R3-S4; 19.2 versions prior to 19.2R2; 19.3 versions prior to 19.3R3; 19.4 versions prior to 19.4R2;
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| OS | 143 | |
| Hardware | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.