CVE-2019-0053

HIGH

Junos OS - Stack-based Buffer Overflow in Telnet Client via Environment Variable Handling

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2019-0053. PoCs published by Hacker Fantastic, dreamsmasher.

AI-analyzed exploit summary The writeup describes stack and heap overflow vulnerabilities in GNU inetutils telnet client (<=1.9.4) due to unbounded environment variable handling, potentially leading to arbitrary code execution. The analysis includes code snippets, exploitation examples, and debug traces.

Description

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.

Exploits (2)

exploitdb WRITEUP
by Hacker Fantastic · textdoslinux
https://www.exploit-db.com/exploits/45982

The writeup describes stack and heap overflow vulnerabilities in GNU inetutils telnet client (<=1.9.4) due to unbounded environment variable handling, potentially leading to arbitrary code execution. The analysis includes code snippets, exploitation examples, and debug traces.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Theoretical
Target: GNU inetutils telnet client <=1.9.4
No auth needed
Prerequisites: Telnet client with vulnerable inetutils version · Ability to control environment variables or telnet server responses
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP 1 stars
by dreamsmasher · poc
https://github.com/dreamsmasher/inetutils-CVE-2019-0053-Patched-PKGBUILD

This repository provides a patched PKGBUILD for inetutils to address CVE-2019-0053, a buffer overflow vulnerability caused by the use of sprintf instead of snprintf. It does not contain exploit code but discusses the vulnerability and mitigation.

Classification
Writeup 90%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: inetutils (unspecified version)
No auth needed
Prerequisites: Access to a vulnerable inetutils installation
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (7)

Core 7
Core References
Exploit, Third Party Advisory, VDB Entry
https://www.exploit-db.com/exploits/45982
Mailing List, Third Party Advisory mailing-list
https://seclists.org/bugtraq/2019/Jul/45
Issue Tracking, Third Party Advisory mailing-list
https://lists.debian.org/debian-lts-announce/2022/11/msg00033.html

Scores

CVSS v3 7.8
EPSS 0.0059
EPSS Percentile 43.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-121 CWE-787
Status published
Products (6)
debian/debian_linux 10.0
juniper/junos 12.3 (13 CPE variants)
juniper/junos 12.3r12
juniper/junos 12.3x48 d10 (13 CPE variants)
juniper/junos 14.1x53 (12 CPE variants)
juniper/junos 15.1 (10 CPE variants)
Published Jul 11, 2019
Tracked Since Feb 18, 2026