Security readout for executives and security teams
Plain-English summary
A Serv-U Console administrator could create, move, or delete files anywhere the Serv-U host account can access. This is serious because compromise or misuse of an admin account could affect sensitive host files, not just files intended for FTP management.
Executive priority
Treat this as a high-priority maintenance and access-control issue, not an emergency internet-wide unauthenticated exploit based on the provided evidence. Prioritize patching affected Serv-U systems and tightening admin access.
Technical view
CVE-2021-35245 is a CWE-284 broken access control issue in SolarWinds Serv-U FTP 15.2.4 Hotfix 1 and earlier. CVSS 3.1 is 8.4, with network access, low complexity, high privileges, user interaction, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to environments running affected SolarWinds Serv-U FTP versions, especially where Serv-U Console admin access exists and the Serv-U host account can reach sensitive local files.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation requires high privileges and user interaction per CVSS, so stolen or misused admin access is the main risk scenario.
Researcher notes
The key boundary failure is that a Serv-U Console admin can operate on any file reachable by the host. Validation should focus on version inventory, admin privilege paths, host account permissions, and evidence of unintended file operations.
Mitigation direction
- Identify all Serv-U FTP deployments and installed versions.
- Upgrade affected versions per SolarWinds advisory and Serv-U 15.2.5 release notes.
- Restrict Serv-U Console admin access to trusted administrators only.
- Limit the Serv-U service account’s file-system permissions where operationally possible.
- Review vendor guidance before applying compensating controls.
Validation and detection
- Confirm no Serv-U FTP instance is 15.2.4 Hotfix 1 or earlier.
- Review Serv-U Console administrator accounts and remove unnecessary access.
- Check host permissions available to the Serv-U service account.
- Review logs for unusual admin file create, move, or delete activity.
- Document patch status and residual exposure for each deployment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-35245 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H1.76Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.4HighVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.solarwinds.com/trust-center/security-advisories/CVE-2021-35245CVE reference · x_refsource_MISC
- https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-2-5_release_notes.htmCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.