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

CVE record · `CVE-2019-0053`

- **Identifiers:** `CVE-2019-0053`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** juniper
- **Weakness (CWE):** [CWE-121](https://cwe.mitre.org/data/definitions/121.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Technologies:** [Juniper Networks Junos OS](https://agentprime.io/advisories/technology/juniper-networks-junos-os.md)
- **Published:** 11 Jul 2019
- **Updated:** 16 Sept 2024
- **Reviewed by a person:** No

Published by the CVE Program (CNA: juniper) at 11 Jul 2019, 19:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Juniper Networks. Product: Junos OS.
  - affected: `12.3 versions prior to 12.3R12-S13`
  - affected: `12.3X48 versions prior to 12.3X48-D80`
  - affected: `14.1X53 versions prior to 14.1X53-D130 and 14.1X53-D49`
  - affected: `15.1 versions prior to 15.1F6-S12 and15.1R7-S4`
  - affected: `15.1X49 versions prior to 15.1X49-D170`
  - affected: `15.1X53 versions prior to 15.1X53-D237 and 15.1X53-D496 and 15.1X53-D591 and 15.1X53-D69`
  - affected: `16.1 versions prior to 16.1R3-S11 and 16.1R7-S4`
  - affected: `16.2 versions prior to 16.2R2-S9`
  - affected: `17.1 versions prior to 17.1R3`
  - affected: `17.2 versions prior to 17.2R1-S8 and 17.2R2-S7 and 17.2R3-S1`
  - affected: `17.3 versions prior to 17.3R3-S4`
  - affected: `17.4 versions prior to 17.4R1-S6 and 17.4R2-S3 and 17.4R3`
  - and 5 more

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 7.8 High, CVSS 3.0: `CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`, from CNA (juniper)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0059, the 48th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Jul 2019. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2019-0053](https://www.cve.org/CVERecord?id=CVE-2019-0053)
- [NVD: CVE-2019-0053](https://nvd.nist.gov/vuln/detail/CVE-2019-0053)

### References from the CNA

- <https://kb.juniper.net/JSA10947>
- <https://www.exploit-db.com/exploits/45982>
- <https://security.freebsd.org/advisories/FreeBSD-SA-19:12.telnet.asc> (vendor-advisory)
- <https://seclists.org/bugtraq/2019/Jul/45> (mailing-list)
- <http://packetstormsecurity.com/files/153746/FreeBSD-Security-Advisory-FreeBSD-SA-19-12.telnet.html>
- <https://lists.debian.org/debian-lts-announce/2022/11/msg00033.html> (mailing-list)
- <https://lists.debian.org/debian-lts-announce/2023/10/msg00013.html> (mailing-list)
- <https://lists.debian.org/debian-lts-announce/2023/10/msg00013.html>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2019-0053>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2019-0053/>. Everything for agents: <https://agentprime.io/llms.txt>.