Juniper Junos Telnet Client Environment Variable memory corruption

Summaryinfo

A vulnerability described as critical has been identified in Juniper Junos. This affects an unknown part of the component Telnet Client. Such manipulation as part of Environment Variable leads to memory corruption. This vulnerability is traded as CVE-2019-0053. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Juniper Junos (Router Operating System) (unknown version). It has been rated as critical. Affected by this issue is an unknown code block of the component Telnet Client. The manipulation as part of a Environment Variable leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffer overflows, which can be exploited to bypass veriexec restrictions on Junos OS. A stack-based overflow is present in the handling of environment variables when connecting via the telnet client to remote telnet servers. This issue only affects the telnet client ? accessible from the CLI or shell ? in Junos OS. Inbound telnet services are not affected by this issue. This issue affects: Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S13; 12.3X48 versions prior to 12.3X48-D80; 14.1X53 versions prior to 14.1X53-D130, 14.1X53-D49; 15.1 versions prior to 15.1F6-S12, 15.1R7-S4; 15.1X49 versions prior to 15.1X49-D170; 15.1X53 versions prior to 15.1X53-D237, 15.1X53-D496, 15.1X53-D591, 15.1X53-D69; 16.1 versions prior to 16.1R3-S11, 16.1R7-S4; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R2-S7, 17.2R3-S1; 17.3 versions prior to 17.3R3-S4; 17.4 versions prior to 17.4R1-S6, 17.4R2-S3, 17.4R3; 18.1 versions prior to 18.1R2-S4, 18.1R3-S3; 18.2 versions prior to 18.2R1-S5, 18.2R2-S2, 18.2R3; 18.2X75 versions prior to 18.2X75-D40; 18.3 versions prior to 18.3R1-S3, 18.3R2; 18.4 versions prior to 18.4R1-S2, 18.4R2.

The weakness was shared 07/11/2019 (Website). The advisory is shared for download at kb.juniper.net. This vulnerability is handled as CVE-2019-0053 since 10/11/2018. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 266306 (Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS : Inetutils vulnerabilities (USN-7781-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (266306). The entries VDB-137743, VDB-137742 and VDB-137740 are related to this item. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos

License

• commercial

Website

• Vendor: https://www.juniper.net/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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