# CVE-2021-0286: Junos OS Evolved: Specially crafted packets may cause the AFT manager process to crash and restart > Attackers can crash the AFT manager process via crafted packets, causing a sustained Denial of Service on Juniper network devices. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 15 Jul 2021 - **Updated:** 16 Sep 2024 - **Also known as:** GHSA-jq9h-7vhv-whc7 ## What is CVE-2021-0286? CVE-2021-0286 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 15 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability in the handling of exceptional conditions in Juniper Networks Junos OS Evolved (EVO) allows an attacker to send specially crafted packets to the device, causing the Advanced Forwarding Toolkit manager (evo-aftmand-bt or evo-aftmand-zx) process to crash and restart, impacting all traffic going through the FPC, resulting in a Denial of Service (DoS). Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. Following messages will be logged prior to the crash: Feb 2 10:14:39 fpc0 evo-aftmand-bt[16263]: [Error] Nexthop: Failed to get fwd nexthop for nexthop:32710470974358 label:1089551617 for session:18 probe:35 Feb 2 10:14:39 fpc0 evo-aftmand-bt[16263]: [Error] Nexthop: Failed to get fwd nexthop for nexthop:19241453497049 label:1089551617 for session:18 probe:37 Feb 2 10:14:39 fpc0 evo-aftmand-bt[16263]: [Error] Nexthop: Failed to get fwd nexthop for nexthop:19241453497049 label:1089551617 for session:18 probe:44 Feb 2 10:14:39 fpc0 evo-aftmand-bt[16263]: [Error] Nexthop: Failed to get fwd nexthop for nexthop:32710470974358 label:1089551617 for session:18 probe:47 Feb 2 10:14:39 fpc0 audit[16263]: ANOM_ABEND auid=4294967295 uid=0 gid=0 ses=4294967295 pid=16263 comm="EvoAftManBt-mai" exe="/usr/sbin/evo-aftmand-bt" sig=11 Feb 2 10:14:39 fpc0 kernel: audit: type=1701 audit(1612260879.272:17): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=16263 comm="EvoAftManBt-mai" exe="/usr/sbin/evo-aftmand-bt" sig=1 This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-EVO; 21.1 versions prior to 21.1R2-EVO. Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions), CWE-703 (Improper Check or Handling of Exceptional Conditions) ## Which versions are affected by CVE-2021-0286? It affects 1 product. Products: Juniper Junos Os Evolved. ## How do I fix CVE-2021-0286? No fix has been published for CVE-2021-0286 yet. Limit exposure of the affected software until one is available. ## Is CVE-2021-0286 being exploited? There is no known exploitation of CVE-2021-0286 in the wild and no public exploit code. ## Other vulnerabilities in Juniper Junos Os Evolved - [CVE-2026-21902](https://insights.sbomify.com/CVE-2026-21902/): Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root (critical 9.3) - [CVE-2023-28983](https://insights.sbomify.com/CVE-2023-28983/): Junos OS Evolved: Shell Injection vulnerability in the gNOI server (high 8.8) - [CVE-2025-21599](https://insights.sbomify.com/CVE-2025-21599/): Denial of service in Junos OS Evolved (high 8.7) - [CVE-2024-47502](https://insights.sbomify.com/CVE-2024-47502/): Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS (high 8.7) - [CVE-2024-39531](https://insights.sbomify.com/CVE-2024-39531/): Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols (high 8.7) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-0286 and fix it if it is affected. What it is: CVE-2021-0286 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 15 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2021-0286 in the wild and no public exploit code. Affected product: Juniper Junos Os Evolved. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2021-0286/ (Markdown: https://insights.sbomify.com/CVE-2021-0286/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0286 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0286 - OSV: https://osv.dev/vulnerability/CVE-2021-0286 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-0286/ Summaries are generated and may contain mistakes; the official description above is the record.