Buffer overflow in Juniper Junos
CVE-2019-0053
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Juniper Junos — versions 12.3, 12.3r12, 12.3x48
- Juniper Networks Junos OS — versions 12.3 versions prior to 12.3R12-S13, 12.3X48 versions prior to 12.3X48-D80, 14.1X53 versions prior to 14.1X53-D130 and 14.1X53-D49
- Debian Linux — versions 10.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- kb.juniper.net/JSA10947 (Vendor Advisory)
- www.exploit-db.com/exploits/45982 (Exploit, VDB Entry, Third Party Advisory)
- security.FreeBSD.org/advisories/FreeBSD-SA-19:12.telnet.asc (vendor-advisory, Third Party Advisory)
- seclists.org/bugtraq/2019/Jul/45 (mailing-list, Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/153746/FreeBSD-Security-Advisory-FreeBSD-SA-19-12… (VDB Entry, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/11/msg00033.html (mailing-list, Third Party Advisory, Issue Tracking)
- lists.debian.org/debian-lts-announce/2023/10/msg00013.html (mailing-list)
Frequently asked questions
- What is CVE-2019-0053?
- CVE-2019-0053 is a high-severity vulnerability in Juniper Junos, classified under Stack-based Buffer Overflow. CVSS score: 7.8/10. Published 2019-07-11.
- How severe is CVE-2019-0053?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2019-0053 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.