CVE-2021-34724 | Cisco IOS XE SD-WAN Software Privilege Escalation Vulnerability

A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to elevate privileges and execute arbitrary code on the underlying operating system as the root user. An attacker must be authenticated on an affected device as a PRIV15 user. This vulnerability is due to insufficient file system protection and the presence of a sensitive file in the bootflash directory on an affected device. An attacker could exploit this vulnerability by overwriting an installer file stored in the bootflash directory with arbitrary commands that can be executed with root-level privileges. A successful exploit could allow the attacker to read and write changes to the configuration database on the affected device.

Published: 2021-09-22 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-34724 is rated Low Risk (30/100): 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-2021-34724

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 0.12% 0.26% +0.13%
2 2025-11-21 0.05% 0.12% +0.08%
3 2025-11-18 — 0.05% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-34724

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 5.2 [email protected]
6.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 5.2 [email protected]
6.6 2.0 MEDIUM
AV:L/AC:L/Au:N/C:C/I:C/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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 9.2 [email protected]

Weakness enumeration for CVE-2021-34724

Affected software / configurations for CVE-2021-34724

Vendor Product Version Raw CPE
cisco ios_xe_sd-wan <= 17.3.1a cpe:2.3:o:cisco:ios_xe_sd-wan:*:*:*:*:*:*:*:*

References for CVE-2021-34724

cvelogic Threat Intelligence