CVE-2021-0242 Detail

Current Description

A vulnerability due to the improper handling of direct memory access (DMA) buffers on EX4300 switches on Juniper Networks Junos OS allows an attacker sending specific unicast frames to trigger a Denial of Service (DoS) condition by exhausting DMA buffers, causing the FPC to crash and the device to restart. The DMA buffer leak is seen when receiving these specific, valid unicast frames on an interface without Layer 2 Protocol Tunneling (L2PT) or dot1x configured. Interfaces with either L2PT or dot1x configured are not vulnerable to this issue. When this issue occurs, DMA buffer usage keeps increasing and the following error log messages may be observed: Apr 14 14:29:34.360 /kernel: pid 64476 (pfex_junos), uid 0: exited on signal 11 (core dumped) Apr 14 14:29:33.790 init: pfe-manager (PID 64476) terminated by signal number 11. Core dumped! The DMA buffers on the FPC can be monitored by the executing vty command 'show heap': ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 4a46000 268435456 238230496 30204960 11 Kernel 1 18a46000 67108864 17618536 49490328 73 Bcm_sdk 2 23737000 117440512 18414552 99025960 84 DMA buf <<<<< keeps increasing 3 2a737000 16777216 16777216 0 0 DMA desc This issue affects Juniper Networks Junos OS on the EX4300: 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R2-S3, 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S1, 20.3R2.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  7.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Nist CVSS score does not match with CNA score
CNA:  Juniper Networks, Inc.
Base Score:  6.5 MEDIUM
Vector:  CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://kb.juniper.net/JSA11135 Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer cwe source acceptance level NIST   Contributor acceptance level Juniper Networks, Inc.  
CWE-241 Improper Handling of Unexpected Data Type Contributor acceptance level Juniper Networks, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-0242
NVD Published Date:
04/22/2021
NVD Last Modified:
04/27/2021
Source:
Juniper Networks, Inc.