How severe is CVE-2020-5142?

CVE-2020-5142 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-2020-5142 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-2020-5142?

CVE-2020-5142 primarily affects Sonicwall Sonicos. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5142?

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

When was CVE-2020-5142 published?

CVE-2020-5142 was published on 2020-10-12 and last updated on 2026-06-17.

CVE-2020-5142

CVE-2020-5142 is a medium-severity vulnerability in Sonicwall Sonicos 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: Sonicwall Sonicos
Published: 2020-10-12
Last modified: 2026-06-17

Description

A stored cross-site scripting (XSS) vulnerability exists in the SonicOS SSLVPN web interface. A remote unauthenticated attacker is able to store and potentially execute arbitrary JavaScript code in the firewall SSLVPN portal. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version SonicOS 7.0.0.0.

Frequently asked questions

What is CVE-2020-5142?: A stored cross-site scripting (XSS) vulnerability exists in the SonicOS SSLVPN web interface. A remote unauthenticated attacker is able to store and potentially execute arbitrary JavaScript code in the firewall SSLVPN portal. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version SonicOS 7.0.0.0.
How severe is CVE-2020-5142?: CVE-2020-5142 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-2020-5142 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-2020-5142?: CVE-2020-5142 primarily affects Sonicwall Sonicos. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5142?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5142 published?: CVE-2020-5142 was published on 2020-10-12 and last updated on 2026-06-17.

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2020-0017

Affected products (3)

cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicos:7.0.0.0:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicosv:*:*:*:*:*:*:*:*

More vulnerabilities in Sonicwall Sonicos

CVE-2025-40600 — Critical (CVSS 9.8): Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote…
CVE-2024-53704 — Critical (CVSS 9.8): An Improper Authentication vulnerability in the SSLVPN authentication mechanism allows a remote attacker to bypass…
CVE-2024-40766 — Critical (CVSS 9.8): An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially…
CVE-2024-22394 — Critical (CVSS 9.8): An improper authentication vulnerability has been identified in SonicWall SonicOS SSL-VPN feature, which in specific…
CVE-2022-22274 — Critical (CVSS 9.8): A Stack-based buffer overflow vulnerability in the SonicOS via HTTP request allows a remote unauthenticated attacker to…
CVE-2020-5135 — Critical (CVSS 9.8): A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially…

All CVEs affecting Sonicwall Sonicos →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →