CVE-2021-34722· NVD / CVE Program· CNA cisco

Cisco IOS XR Software Command Injection Vulnerabilities

Noroxi assessment

Priority: Monitor (action score 26/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.28% (FIRST EPSS).
Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Multiple vulnerabilities in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to gain access to the underlying root shell of an affected device and execute arbitrary commands with root privileges. For more information about these vulnerabilities, see the Details section of this advisory.

MediumCVSS 6.7 · v3.1—No exploit No fix recorded

BDU:2021-04732

Published: Sep 9, 2021
Updated: Jun 16, 2026
EPSS: 0.2% · 19th percentile
CWE: CWE-78

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 6.7
CNA · cisco: 6.7; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
cisco	ios xr	cpe:2.3:o:cisco:ios_xr
cisco	asr 9000v-v2	cpe:2.3:h:cisco:asr_9000v-v2
cisco	asr 9001	cpe:2.3:h:cisco:asr_9001
cisco	asr 9006	cpe:2.3:h:cisco:asr_9006
cisco	asr 9010	cpe:2.3:h:cisco:asr_9010
cisco	asr 9901	cpe:2.3:h:cisco:asr_9901
cisco	asr 9902	cpe:2.3:h:cisco:asr_9902
cisco	asr 9903	cpe:2.3:h:cisco:asr_9903
cisco	asr 9904	cpe:2.3:h:cisco:asr_9904
cisco	asr 9906	cpe:2.3:h:cisco:asr_9906
cisco	asr 9910	cpe:2.3:h:cisco:asr_9910
cisco	asr 9912	cpe:2.3:h:cisco:asr_9912

and 32 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

cisco ios xr7.1.1 and later · before 7.3.2
cisco ios xr7.4.0 and later · before 7.4.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

Cisco Cisco IOS XR Software
- n/aaffected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

CVE-2020-3118Cisco IOS XR Software Cisco Discovery Protocol Format String VulnerabilityKEV
69This week
CVE-2020-3569Cisco IOS XR Software DVMRP Memory Exhaustion VulnerabilitiesKEV
65This week
CVE-2020-3566Cisco IOS XR Software DVMRP Memory Exhaustion VulnerabilityKEV
65This week

Published before and after this one in the same product

← EarlierCVE-2021-34720Sep 9, 2021 · Cisco IOS XR Software IP Service Level Agreements and Two-Way Active Measurement Protocol Denial of Service Vulnerability
34Monitor
← EarlierCVE-2021-34721Sep 9, 2021 · Cisco IOS XR Software Command Injection Vulnerabilities
26Monitor
Later →CVE-2021-34728Sep 9, 2021 · Cisco IOS XR Software Authenticated User Privilege Escalation Vulnerabilities
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0720 · Sep 9, 2021(Cisco Güvenlik Zafiyeti)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
Administrator privileges are required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: High
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

User input is inserted as text into a shell command. The shell may interpret special characters in the input as part of the command.

The bug in code

The whole CWE-78 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const host = req.body.host;
2exec("ping -c 1 " + host, onResult);

Fixed

1const host = req.body.host;
2if (!/^[a-z0-9.-]{1,253}$/i.test(host)) return res.sendStatus(400);
3execFile("ping", ["-c", "1", host], onResult);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-cmd-inj-wbZKvPxc

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records