CASCACascade Atlas

Evidence dossier

CVE-2021-35211

Serv-U Remote Memory Escape Vulnerability

81.6–99.1Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.

State
PUBLISHED
Published
Jul 14, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS91.16%

2026-07-18 · v2026.06.15 · percentile 99.8%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

SolarWindsoriginal assertion
container

Serv-U Remote Memory Escape Vulnerability

CISA KEVoriginal assertion
observed_exploitation

SolarWinds Serv-U Remote Code Execution Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.911600000000; percentile 0.997980000000

Applicability

Cited product scope

Trace impact →
SolarWindsServ-U Managed File Transfer Server and Serv-U Secured FTP
[{"status": "affected", "version": "SolarWinds Serv-U", "lessThan": "15.2.3 HF1", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:*; end excluding 15.2.3supported
Unknown vendorUnknown product
cpe:2.3:a:solarwinds:serv-u:15.2.3:-:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:solarwinds:serv-u:15.2.3:hotfix1:*:*:*:*:*:*supported

Assessments

CVSS by origin

10.0
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
10.0
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:L/Au:N/C:C/I:C/A:C
9.0
psirt@solarwinds.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
9.0
SolarWindsCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.