CVE-2019-0053

Junos OS: Insufficient validation of environment variables in telnet client may lead to stack-based buffer overflow

HIGH

7.8

CVSS Score

Published: July 11, 2019 at 07:40 PM UTC

Updated: June 17, 2026 at 02:07 AM UTC

2 products affected across 2 vendorsDebian LinuxJunos

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Severity

HIGH7.8

Exploit prediction

EPSS 0.6%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Debian Linux · Debiandrupal

95%

10.0

Junos · Juniper Networks

95%

v < 12.3R12-S13v < 12.3X48-D80v < 14.1X53-D130v < 15.1F6-S12v < 15.1X49-D170v < 15.1X53-D237v < 16.1R3-S11v < 16.2R2-S9v < 17.1R3v < 17.2R1-S8v < 17.3R3-S4v < 17.4R1-S6v < 18.1R2-S4v < 18.2R1-S5v < 18.2X75-D40v < 18.3R1-S3v < 18.4R1-S212.3 12.3 r1 12.3 r11 12.3 r12 12.3 r13 12.3 r2 12.3 r3 12.3 r4 12.3 r5 12.3 r6 12.3 r7 12.3 r8 12.3 r912.3r1212.3x48 d10 12.3x48 d15 12.3x48 d25 12.3x48 d30 12.3x48 d35 12.3x48 d40 12.3x48 d45 12.3x48 d50 12.3x48 d55 12.3x48 d60 12.3x48 d65 12.3x48 d70 12.3x48 d7514.1x5314.1x53 d10 14.1x53 d15 14.1x53 d16 14.1x53 d25 14.1x53 d26 14.1x53 d27 14.1x53 d30 14.1x53 d35 14.1x53 d40 14.1x53 d45 14.1x53 d48 15.1 15.1 a1 15.1 f1 15.1 f2 15.1 f2-s1 15.1 f2-s2 15.1 f2-s3 15.1 f2-s4 15.1 f3 15.1 f4 15.1 f5 15.1 f6 15.1 f6-s3 15.1 r1 15.1 r2 15.1 r3 15.1 r4 15.1 r4-s9 15.1 r5 15.1 r6 15.1 r6-s6 15.1 r7-s1 15.1 r7-s2 15.1 r7-s315.1x4915.1x49 d10 15.1x49 d100 15.1x49 d110 15.1x49 d120 15.1x49 d130 15.1x49 d140 15.1x49 d150 15.1x49 d160 15.1x49 d20 15.1x49 d30 15.1x49 d35 15.1x49 d40 15.1x49 d45 15.1x49 d50 15.1x49 d55 15.1x49 d60 15.1x49 d65 15.1x49 d70 15.1x49 d75 15.1x49 d80 15.1x49 d9015.1x5315.1x53 d20 15.1x53 d21 15.1x53 d210 15.1x53 d230 15.1x53 d231 15.1x53 d23215.1x53 d23315.1x53 d234 15.1x53 d235 15.1x53 d236 15.1x53 d25 15.1x53 d30 15.1x53 d32 15.1x53 d33 15.1x53 d34 15.1x53 d40 15.1x53 d45 15.1x53 d495 15.1x53 d52 15.1x53 d55 15.1x53 d5615.1x53 d5915.1x53 d590 15.1x53 d60 15.1x53 d61 15.1x53 d62 15.1x53 d63 15.1x53 d64 15.1x53 d65 15.1x53 d6615.1x53 d6715.1x53 d68 15.1x53 d70 16.1 16.1 r1 16.1 r2 16.1 r3 16.1 r3-s10 16.1 r3-s11 16.1 r4 16.1 r5 16.1 r6 16.1 r7 16.2 16.2 r1 16.2 r2 16.2 r2-s1 16.2 r2-s2 16.2 r2-s5 16.2 r2-s6 16.2 r2-s7 16.2 r2-s8 17.1 17.1 r1 17.1 r2-s1 17.1 r2-s10 17.1 r2-s2 17.1 r2-s3 17.1 r2-s4 17.1 r2-s5 17.1 r2-s6 17.1 r2-s7 17.2 17.2 r1 17.2 r1-s2 17.2 r1-s4 17.2 r1-s7 17.2 r2 17.2 r2-s6 17.3 17.3 r1 17.3 r2 17.3 r2-s1 17.3 r2-s2 17.3 r3-s1 17.3 r3-s2 17.3 r3-s3 17.4 17.4 r1 17.4 r1-s1 17.4 r1-s2 17.4 r1-s4 17.4 r2 17.4 r2-s1 17.4 r2-s2 18.1 18.1 r1 18.1 r2 18.1 r2-s1 18.1 r2-s2 18.1 r3 18.1 r3-s2 18.2 18.2 r1 18.2 r1-s3 18.2 r1-s4 18.2 r2-s118.2x7518.2x75 d20 18.3 18.3 r1 18.3 r1-s1 18.3 r1-s2 18.4 18.4 r1 18.4 r1-s1

Affected range stops below 12.3R12-S13, so it looks safe — our inference, not a vendor statement

Affected range stops below 12.3X48-D80, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.1X53-D130, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1F6-S12, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X49-D170, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X53-D237, so it looks safe — our inference, not a vendor statement

Affected range stops below 16.1R3-S11, so it looks safe — our inference, not a vendor statement

Affected range stops below 16.2R2-S9, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.2R1-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.3R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.4R1-S6, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.1R2-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2R1-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2X75-D40, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.3R1-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.4R1-S2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (7)

Third Party AdvisoryVDB Entry

Source: [email protected]

http://packetstormsecurity.com/files/153746/FreeBSD-Security-Advisory-FreeBSD-SA-19-12.telnet.html

Vendor Advisory

Source: [email protected]

https://kb.juniper.net/JSA10947

Mailing ListIssue TrackingThird Party Advisory

Source: [email protected]

https://lists.debian.org/debian-lts-announce/2022/11/msg00033.html

Mailing List

Source: [email protected]

https://lists.debian.org/debian-lts-announce/2023/10/msg00013.html

Mailing ListThird Party Advisory

Source: [email protected]

https://seclists.org/bugtraq/2019/Jul/45

Vendor AdvisoryThird Party Advisory

Source: [email protected]

https://security.FreeBSD.org/advisories/FreeBSD-SA-19:12.telnet.asc

ExploitThird Party AdvisoryVDB Entry

Source: [email protected]

https://www.exploit-db.com/exploits/45982

CVSS

7.8HIGH[email protected]

Attack Vector: LOCAL
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-121CWE-787

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