How severe is CVE-2021-1391?

CVE-2021-1391 has a CVSS 3.x base score of 5.1, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.

Is CVE-2021-1391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1391?

CVE-2021-1391 primarily affects Cisco Ios. In total, 134 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1391?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-1391 published?

CVE-2021-1391 was published on 2021-03-24 and last updated on 2026-06-17.

CVE-2021-1391

CVE-2021-1391 is a medium-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 5.1. 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-489.

Key facts

Severity: Medium (CVSS 3.x base score 5.1)
CVSS v2: 7.2
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-489
Affected product: Cisco Ios
Published: 2021-03-24
Last modified: 2026-06-17

Description

A vulnerability in the dragonite debugger of Cisco IOS XE Software could allow an authenticated, local attacker to escalate from privilege level 15 to root privilege. The vulnerability is due to the presence of development testing and verification scripts that remained on the device. An attacker could exploit this vulnerability by bypassing the consent token mechanism with the residual scripts on the affected device. A successful exploit could allow the attacker to escalate from privilege level 15 to root privilege.

Frequently asked questions

What is CVE-2021-1391?: A vulnerability in the dragonite debugger of Cisco IOS XE Software could allow an authenticated, local attacker to escalate from privilege level 15 to root privilege. The vulnerability is due to the presence of development testing and verification scripts that remained on the device. An attacker could exploit this vulnerability by bypassing the consent token mechanism with the residual scripts on the affected device. A successful exploit could allow the attacker to escalate from privilege level 15 to root privilege.
How severe is CVE-2021-1391?: CVE-2021-1391 has a CVSS 3.x base score of 5.1, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2021-1391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1391?: CVE-2021-1391 primarily affects Cisco Ios. In total, 134 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1391?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1391 published?: CVE-2021-1391 was published on 2021-03-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-XE-FSM-Yj8qJbJc

Affected products (134)

cpe:2.3:o:cisco:ios:12.2\(6\)i1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.0\(2\)se13a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(3\)svr1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(3\)svr2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(3\)svr3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(3\)svs:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.1\(3\)svs1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(4\)ea10:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)e1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)e2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)e2b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)e2c:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)ea:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5\)ex:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5a\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5a\)e1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5b\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(5c\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e0a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e0c:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e1s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e2a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e2b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)e3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(6\)eb:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e0a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e0b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e0s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e2a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e2b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.2\(7\)e3:*:*:*:*:*:*:*

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