CVE-2021-34711 | Cisco IP Phone Software Arbitrary File Read Vulnerability

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 update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-34711 is rated Low Risk (28.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.26%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-34711

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.26% +0.20%
2 2025-03-17 0.04% 0.06% +0.02%
3 2023-03-07 — 0.04% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-34711

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-34711

Affected software / configurations for CVE-2021-34711

Vendor Product Version Raw CPE
cisco ip_conference_phone_7832_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_8832_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7811_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_7811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7821_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_7821_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7832_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_7832_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7841_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_7841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7861_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_7861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8811_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8831_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8831_firmware:*:*:*:*:*:*:*:*
cisco ip_phones_8832_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phones_8832_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8841_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8845_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8845_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8851_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8851_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8861_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8865_firmware < 14.1\(1\) cpe:2.3:o:cisco:ip_phone_8865_firmware:*:*:*:*:*:*:*:*
cisco wireless_ip_phone_8821_firmware < 11.0\(6\)sr2 cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-34711

cvelogic Threat Intelligence