CVE-2021-0217
What it is
A vulnerability in processing of certain DHCP packets from adjacent clients on EX Series and QFX Series switches running Juniper Networks Junos OS with DHCP local/relay server configured may lead to exhaustion of DMA memory causing a Denial of Service (DoS). Over time, exploitation of this vulnerability may cause traffic to stop being forwarded, or to crashing of the fxpc process. When Packet DMA heap utilization reaches 99%, the system will become unstable. Packet DMA heap utilization can be monitored through the following command: user@junos# request pfe execute target fpc0 timeout 30 command "show heap" ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 213301a8 536870488 387228840 149641648 27 Kernel 1 91800000 8388608 3735120 4653488 55 DMA 2 92000000 75497472 74452192 1045280 1 PKT DMA DESC 3 d330000 335544320 257091400 78452920 23 Bcm_sdk 4 96800000 184549376 2408 184546968 99 Packet DMA <--- 5 903fffe0 20971504 20971504 0 0 Blob An indication of the issue occurring may be observed through the following log messages: Dec 10 08:07:00.124 2020 hostname fpc0 brcm_pkt_buf_alloc:523 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.126 2020 hostname fpc0 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.128 2020 hostname fpc0 brcm_pkt_buf_alloc:523 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.130 2020 hostnameC fpc0 (buf alloc) failed allocating packet buffer This issue affects Juniper Networks Junos OS on EX Series and QFX Series: 17.4R3 versions prior to 17.4R3-S3; 18.1R3 versions between 18.1R3-S6 and 18.1R3-S11; 18.2R3 versions prior to 18.2R3-S6; 18.3R3 versions prior to 18.3R3-S4; 18.4R2 versions prior to 18.4R2-S5; 18.4R3 versions prior to 18.4R3-S6; 19.1 versions between 19.1R2 and 19.1R3-S3; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S2, 20.2R2. Junos OS versions prior to 17.4R3 are unaffected by this vulnerability.
At a glance
- Exploitability
- Can be exploited from the same network segment without logging in. High risk of service disruption.
- Exploit odds
- 0.7% 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: 0.7% in the next 30 days (EPSS).
- Severity: 7.4 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-119 · Buffer errors
- Record status
- Modified
Affected
- Juniper Junos 17.4
- Juniper Junos 18.1
- Juniper Junos 18.2
- Juniper Junos 18.3
- Juniper Junos 18.4
- Juniper Junos 19.1
- Juniper Junos 19.2
- Juniper Junos 19.3
Attack profile CVSS 3.1 · 7.4
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/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-2021-0217.md and follow it. Check whether this project is affected by CVE-2021-0217. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
