High Injection

CVE-2021-1432 — Cisco IOS XE SD-WAN Software Arbitrary Command Execution Vulnerability

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system as the root user. The attacker must be authenticated on the affected device as a low-privileged user to exploit this vulnerability. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by injecting arbitrary commands to a file as a lower-privileged user. The commands are then executed on the device by the root user. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

Published Mar 24, 2021 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: cisco

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.4% (30-day exploitation probability)+4
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.35%

ahead of 27% of scored CVEs · Oct 14, 2026

Affects

Cisco

Ios Xe and 1 more

CVSS base

7.3

High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Cisco Ios Xe, Cisco Ios Xe Sd-wan).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cisco	Ios Xe	version 3.15.2xbsversion 17.2.1vversion 17.2.1rversion 17.2.1aversion 17.2.1version 16.12.4aversion 16.12.4version 16.12.3s and 17 more version 16.12.3aversion 16.12.3version 16.12.2tversion 16.12.2sversion 16.12.2aversion 16.12.2version 16.12.1zaversion 16.12.1zversion 16.12.1yversion 16.12.1xversion 16.12.1wversion 16.12.1tversion 16.12.1sversion 16.12.1cversion 16.12.1aversion 16.12.1version 3.15.1xbs	Vulnerable	NIST National Vulnerability Database
Cisco	Ios Xe Sd-wan	versions not specified by the source	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.3	CVSS 3.1	High	1.3	5.9	psirt@cisco.com via NIST National Vulnerability Database
7.3	CVSS 3.1	High	1.3	5.9	nvd@nist.gov via NIST National Vulnerability Database
7.3	CVSS 3.1	High	—	—	cisco via CVE Program (cve.org) e CISA ADP
6.9	CVSS 2.0	Medium	3.4	10.0	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-74 · Injection

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.35%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Look for parameters with command/query metacharacters and unexpected child processes of the service.

endpoint telemetry (EDR)application logs

Timeline

What happened to this CVE, newest first.

2026
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.3
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2021
CVE published
Mar 24, 2021 · cisco

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-sdwarbcm
Vendor Advisory, vendor-advisory, x_refsource_CISCO, NIST National Vulnerability Database

Elsewhere on this site

Cisco
every CVE for this vendor

Injection
same class

CWE-74
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-20301 Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Service Vulnerability Aug 5, 2026
High CVE-2026-20273 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
Critical CVE-2026-20272 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
High CVE-2026-20271 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
High CVE-2026-20269 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
High CVE-2026-20270 Cisco IOS XE Software Security Hardening Release Aug 5, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2021-1432 is "Cisco IOS XE SD-WAN Software Arbitrary Command Execution Vulnerability", rated High. It affects Ios Xe (Cisco); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.3 describes technical severity. EPSS 0.35% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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