What is CVE-2021-34711?

CVE-2021-34711 is a medium-severity vulnerability in Cisco Ip Phones With Multiplatform Firmware, classified under Absolute Path Traversal. CVSS score: 5.5/10. Published 2021-10-06.

How severe is CVE-2021-34711?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Path Traversal in Cisco Ip Phones With Multiplatform Firmware

CVE-2021-34711

A vulnerability in the debug shell of Cisco IP Phone software could allow an authenticated, local attacker to read any file on the device file system. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by providing crafted input to a debug shell command. A successful exploit could allow the attacker to read any file on the device file system.

Published 2021-10-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (18.6th percentile), scored 2026-11-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipphone-… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-34711?: CVE-2021-34711 is a medium-severity vulnerability in Cisco Ip Phones With Multiplatform Firmware, classified under Absolute Path Traversal. CVSS score: 5.5/10. Published 2021-10-06.
How severe is CVE-2021-34711?: Medium severity. CVSS v3 base score is 5.5 out of 10.