How severe is CVE-2021-1529?

CVE-2021-1529 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-1529 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1529?

CVE-2021-1529 primarily affects Cisco Ios Xe. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1529?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-1529 published?

CVE-2021-1529 was published on 2021-10-21 and last updated on 2026-06-17.

CVE-2021-1529

CVE-2021-1529 is a high-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.9
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Cisco Ios Xe
Published: 2021-10-21
Last modified: 2026-06-17

Description

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. The vulnerability is due to insufficient input validation by the system CLI. An attacker could exploit this vulnerability by authenticating to an affected device and submitting crafted input to the system CLI. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges.

Frequently asked questions

What is CVE-2021-1529?: A vulnerability in the CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. The vulnerability is due to insufficient input validation by the system CLI. An attacker could exploit this vulnerability by authenticating to an affected device and submitting crafted input to the system CLI. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges.
How severe is CVE-2021-1529?: CVE-2021-1529 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-1529 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1529?: CVE-2021-1529 primarily affects Cisco Ios Xe. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1529?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-1529 published?: CVE-2021-1529 was published on 2021-10-21 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-rhpbE34A

Affected products (3)

cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:17.6.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe_sd-wan:*:*:*:*:*:*:*:*

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