How severe is CVE-2020-3121?

CVE-2020-3121 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-3121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3121?

CVE-2020-3121 primarily affects Cisco Sg250x-24 Firmware. In total, 45 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3121?

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

When was CVE-2020-3121 published?

CVE-2020-3121 was published on 2020-01-26 and last updated on 2026-06-17.

CVE-2020-3121

CVE-2020-3121 is a medium-severity vulnerability in Cisco Sg250x-24 Firmware with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Cisco Sg250x-24 Firmware
Published: 2020-01-26
Last modified: 2026-06-17

Description

A vulnerability in the web-based management interface of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected device. An attacker could exploit this vulnerability by persuading a user of the interface to click a malicious link and access a specific page. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

Frequently asked questions

What is CVE-2020-3121?: A vulnerability in the web-based management interface of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected device. An attacker could exploit this vulnerability by persuading a user of the interface to click a malicious link and access a specific page. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.
How severe is CVE-2020-3121?: CVE-2020-3121 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-3121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3121?: CVE-2020-3121 primarily affects Cisco Sg250x-24 Firmware. In total, 45 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3121?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3121 published?: CVE-2020-3121 was published on 2020-01-26 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-sbsms-xss

Affected products (45)

cpe:2.3:o:cisco:sg250x-24_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250x-24p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250x-48_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250x-48p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-08_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-08hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-10p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-18_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-26_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-26hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-26p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-50_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-50hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-50p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-24_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-24p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-48_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg250-48hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sf350-48_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sf350-48p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sf350-48mp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-10p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-10mp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg355-10mp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-28_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-28p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg350-28mp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sx550x-16ft_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sx550x-24ft_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sx550x-12ft_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sx550x-24_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sx550x-52_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-24_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-24p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-24mp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-24mpp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-48_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-48p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:sg550x-48mp_firmware:*:*:*:*:*:*:*:*

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