No exploitation reportedFix available

CVE-2021-42854

Q: Is CVE-2021-42854 actively exploited?

Active exploitation of CVE-2021-42854 has not been confirmed. Its EPSS score was 1.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-42854?

CVE-2021-42854 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2022-03-10
Fixed in12.13.0 · 11.8.8
WeaknessCWE-20 · CWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) PluginServlet has directory traversal vulnerabilities at the "/api/appInternals/1.0/plugin/pmx" API. The affected endpoint does not have any input validation of the user's input that allows a malicious payload to be injected.

Timeline

dates in UTC

2022-03-1017:44CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-42854?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-42854?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Riverbed steelcentral appinternals dynamic sampling agent

Branch	Affected	Fixed in	Source
12.x	≥ 12.0.0, < 12.13.0	12.13.0	NVD
11.x	≥ 11.0.0, < 11.8.8	11.8.8	NVD
10.0	= 10.0.0	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Riverbed steelcentral appinternals dynamic sampling agent to 12.13.0 · 11.8.8

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.19.8read 2026-10-23
NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
CNAweakness (CWE)CWE-20read 2026-10-23
NVDweakness (CWE)CWE-22read 2026-10-23
FIRST EPSSEPSS score1.6 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2022-03-10
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-42854?

Is CVE-2021-42854 actively exploited?

Active exploitation of CVE-2021-42854 has not been confirmed. Its EPSS score was 1.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-42854?

CVE-2021-42854 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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