CVE-2021-35211

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17. Known ransomware campaign use: reported by CISA.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

91.16% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.8% of scored records. A rank, not a probability.

NVD base score

10.0 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-07-14 20:55Z5 YR AGO

Last updated

2025-10-21 23:25Z1 YR AGO

Reserved

2021-06-22

Assigning CNA

SolarWinds

Record state

PUBLISHED

Severity

Critical (CVSS 9.0)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.1

Document digest

480ef8574385ee982d614869ed988631f7b1f2d7bd5718777eea35a14b089036

• www.solarwinds.comhttps://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211x_refsource_MISC
• www.microsoft.comhttps://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploitx_refsource_MISC
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211government-resource