How severe is CVE-2021-42856?

CVE-2021-42856 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-42856 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42856?

CVE-2021-42856 primarily affects Riverbed Steelcentral Appinternals Dynamic Sampling Agent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-42856?

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

When was CVE-2021-42856 published?

CVE-2021-42856 was published on 2022-03-10 and last updated on 2026-06-17.

CVE-2021-42856

CVE-2021-42856 is a medium-severity vulnerability in Riverbed Steelcentral Appinternals Dynamic Sampling Agent with a CVSS 3.x base score of 4.7. 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 4.7)
CVSS v2: 4.3
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Riverbed Steelcentral Appinternals Dynamic Sampling Agent
Published: 2022-03-10
Last modified: 2026-06-17

Description

It was discovered that the /DsaDataTest endpoint is susceptible to Cross-site scripting (XSS) attack. It was noted that the Metric parameter does not have any input checks on the user input that allows an attacker to craft its own malicious payload to trigger a XSS vulnerability.

Frequently asked questions

What is CVE-2021-42856?: It was discovered that the /DsaDataTest endpoint is susceptible to Cross-site scripting (XSS) attack. It was noted that the Metric parameter does not have any input checks on the user input that allows an attacker to craft its own malicious payload to trigger a XSS vulnerability.
How severe is CVE-2021-42856?: CVE-2021-42856 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-42856 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42856?: CVE-2021-42856 primarily affects Riverbed Steelcentral Appinternals Dynamic Sampling Agent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-42856?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42856 published?: CVE-2021-42856 was published on 2022-03-10 and last updated on 2026-06-17.

References

https://aternity.force.com/customersuccess/s/article/Reflected-Cross-site-Scripting-at-DsaDataTest-CVE-2021-42856

Affected products (2)

cpe:2.3:a:riverbed:steelcentral_appinternals_dynamic_sampling_agent:*:*:*:*:*:*:*:*
cpe:2.3:a:riverbed:steelcentral_appinternals_dynamic_sampling_agent:10.0.0:*:*:*:*:*:*:*

More vulnerabilities in Riverbed Steelcentral Appinternals Dynamic Sampling Agent

CVE-2021-42854 — Critical (CVSS 9.8): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) PluginServlet has directory…
CVE-2021-42786 — Critical (CVSS 9.8): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent (DSA) has Remote Code Execution…
CVE-2021-42787 — Critical (CVSS 9.4): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) AgentConfigurationServlet has…
CVE-2021-42853 — Critical (CVSS 9.1): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) AgentDiagnosticServlet has…
CVE-2021-42855 — High (CVSS 7.8): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent (DSA) uses the ".debug_command.config" file…
CVE-2021-42857 — Medium (CVSS 5.3): It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) AgentDaServlet has directory…

All CVEs affecting Riverbed Steelcentral Appinternals Dynamic Sampling Agent →

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 →