Vulnerability identifier: #VU19149

Vulnerability risk: Medium

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-0053

CWE-ID: CWE-121

Exploitation vector: Local

Exploit availability: No

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

Vendor: Juniper Networks, Inc.

Description

The vulnerability allows a local attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient validation of environment variables when connecting via the telnet client to remote telnet servers. A local authenticated attacker can trigger stack-based buffer overflow, bypass veriexec restrictions and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

This vulnerability only affects the telnet client - accessible from the CLI or shel.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 12.3R12-S12, 12.3x48 - 12.3X48-D77, 14.1x53 - 14.1X53-D122, 15.1R - 15.1R7-S3, 15.1F - 15.1F6-S10, 15.1X49 - 15.1X49-D161, 15.1X53 - 15.1X53-D236, 16.1 - 16.1R3-S10, 16.2 - 16.2R2-S8, 17.1 - 17.1R2-S10, 17.2 - 17.2R1-S7, 17.3 - 17.3R3-S3, 17.4 - 17.4R2, 18.1 - 18.1R2-S3, 18.2X75-D5 - 18.2X75-D30, 18.2 - 18.2R1-S4, 18.3 - 18.3R1-S2, 18.4R1 - 18.4R1-S1

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External links
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10947&cat=SIRT_1&actp=LIST

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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