CVE-2021-0289

Katalog CVE

CVSS 5.3 · Medium EPSS 0,26%

Kerentanan Time-of-check Time-of-use (TOCTOU) Race Condition pada juniper junos. Skor CVSS 3.1 5.3 (Medium) menurut NVD.

Deskripsi (NVD)

When user-defined ARP Policer is configured and applied on one or more Aggregated Ethernet (AE) interface units, a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability between the Device Control Daemon (DCD) and firewall process (dfwd) daemons of Juniper Networks Junos OS allows an attacker to bypass the user-defined ARP Policer. In this particular case the User ARP policer is replaced with default ARP policer. To review the desired ARP Policers and actual state one can run the command "show interfaces <> extensive" and review the output. See further details below. An example output is: show interfaces extensive | match policer Policer: Input: __default_arp_policer__ <<< incorrect if user ARP Policer was applied on an AE interface and the default ARP Policer is displayed Policer: Input: jtac-arp-ae5.317-inet-arp <<< correct if user ARP Policer was applied on an AE interface For all platforms, except SRX Series: This issue affects Juniper Networks Junos OS: All versions 5.6R1 and all later versions prior to 18.4 versions prior to 18.4R2-S9, 18.4R3-S9 with the exception of 15.1 versions 15.1R7-S10 and later versions; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3-S2; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2; This issue does not affect Juniper Networks Junos OS versions prior to 5.6R1. On SRX Series this issue affects Juniper Networks Junos OS: 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.4 versions prior to 19.4R3-S4; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3-S2; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. This issue does not affect 18.4 versions prior to 18.4R1 on SRX Series. This issue does not affect Junos OS Evolved.

Rincian

Terbit di NVD

15 Juli 2021

Terakhir diubah

17 Juni 2026

Status NVD

Modified

CVSS 3.1

5.3 (Medium), sumber NVD
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition

EPSS (30 hari)

0,26% peluang dieksploitasi; lebih tinggi dari 16,5% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD. Ditampilkan 60 dari 68 konfigurasi; daftar lengkap ada di NVD.

Referensi dan perbaikan

• https://kb.juniper.net/JSA11191 advisory vendor