CVE-2021-0216
What it is
A vulnerability in Juniper Networks Junos OS running on the ACX5448 and ACX710 platforms may cause BFD sessions to flap when a high rate of transit ARP packets are received. This, in turn, may impact routing protocols and network stability, leading to a Denial of Service (DoS) condition. When a high rate of transit ARP packets are exceptioned to the CPU and BFD flaps, the following log messages may be seen: bfdd[15864]: BFDD_STATE_UP_TO_DOWN: BFD Session 192.168.14.3 (IFL 232) state Up -> Down LD/RD(17/19) Up time:11:38:17 Local diag: CtlExpire Remote diag: None Reason: Detect Timer Expiry. bfdd[15864]: BFDD_TRAP_SHOP_STATE_DOWN: local discriminator: 17, new state: down, interface: irb.998, peer addr: 192.168.14.3 rpd[15839]: RPD_ISIS_ADJDOWN: IS-IS lost L2 adjacency to peer on irb.998, reason: BFD Session Down bfdd[15864]: BFDD_TRAP_SHOP_STATE_UP: local discriminator: 17, new state: up, interface: irb.998, peer addr: 192.168.14.3 This issue only affects the ACX5448 Series and ACX710 Series routers. No other products or platforms are affected by this vulnerability. This issue affects Juniper Networks Junos OS: 18.2 versions prior to 18.2R3-S8 on ACX5448; 18.3 versions prior to 18.3R3-S5 on ACX5448; 18.4 versions prior to 18.4R1-S6, 18.4R3-S7 on ACX5448; 19.1 versions prior to 19.1R3-S5 on ACX5448; 19.2 versions prior to 19.2R2, 19.2R3 on ACX5448; 19.3 versions prior to 19.3R3 on ACX5448; 19.4 versions prior to 19.4R3 on ACX5448; 20.1 versions prior to 20.1R2 on ACX5448; 20.2 versions prior to 20.2R2 on ACX5448 and ACX710.
At a glance
- Exploitability
- Can be exploited from the same network segment without logging in. High risk of service disruption.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Record status
- Modified
Affected
- Juniper Junos 20.2
- Juniper Junos 18.2
- Juniper Junos 18.3
- Juniper Junos 18.4
- Juniper Junos 19.1
- Juniper Junos 19.2
- Juniper Junos 19.3
- Juniper Junos 19.4
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-0216.md and follow it. Check whether this project is affected by CVE-2021-0216. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
