Vulnerability identifier: #VU52284

Vulnerability risk: Medium

CVSSv3.1: 4.9 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-0247

CWE-ID: CWE-362

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Juniper Junos OS
Operating systems & Components / Operating system

Vendor: Juniper Networks, Inc.

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to a race condition in the firewall process (dfwd). A remote attacker can bypass the firewall rule sets applied to the input loopback filter on any interfaces of a device.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 14.1 - 14.1x51, 14.1x53 - 14.1X53-D51, 15.1 - 15.1R7-S13, 15.1F - 15.1F7-S2, 15.1X49 - 15.1X49-D240, 15.1X49-D210, 15.1X53 - 15.1X53-D592, 18.1 - 18.1R3-S8, 18.2 - 18.2R3-S2, 19.1 - 19.1R2-S3, 18.3 - 18.3R3, 17.1 - 17.1R3-S1, 16.1 - 16.1R7-S6, 19.2 - 19.2R1-S9, 17.4 - 17.4R2-S13, 17.3 - 17.3R3-S6, 17.2 - 17.2R3-S2, 18.4 - 18.4R2-S10, 19.3, 19.2R1-S4, 16.2 - 16.2R2-S10

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External links
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA11140&cat=SIRT_1&actp=LIST

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.