Security readout for executives and security teams
Plain-English summary
Serv-U FTP Server 15.3.0 reportedly used a common encryption key across deployments. If an attacker obtains an encrypted value, they may be able to recover the plaintext. The primary business risk is confidentiality loss from systems handling file-transfer data or credentials.
Executive priority
Treat as a high-priority confidentiality issue for any Serv-U 15.3.0 deployment, especially if externally accessible. Prioritize inventory, vendor-guided remediation, and secret review over emergency incident response unless local evidence suggests exposure.
Technical view
CVE-2021-35252 is a CWE-798 hard-coded/common key issue in SolarWinds Serv-U FTP Server 15.3.0. CVSS 3.1 is 7.5, network exploitable, low complexity, no privileges, no user interaction, with high confidentiality impact only. The sources do not specify the exposed encrypted value type.
Likely exposure
Exposure appears limited to SolarWinds Serv-U FTP Server version 15.3.0, with other versions marked unaffected in the supplied CVE data. Internet-reachable or broadly accessible Serv-U deployments carry higher practical risk.
Exploitation context
The CVE is not listed as KEV in the source bundle, and no cited source states active exploitation. Exploitation depends on an attacker obtaining an encrypted value; the bundle does not describe how that value becomes exposed.
Researcher notes
The source bundle identifies the weakness and affected version but omits important operational details, including encrypted value locations, patch version wording, and proof of exploitation. Avoid assuming impact beyond plaintext recovery from an exposed encrypted value.
Mitigation direction
- Inventory Serv-U FTP Server deployments and identify any version 15.3.0 instances.
- Review SolarWinds advisory and 15.3.2 release notes for vendor-approved upgrade guidance.
- Restrict Serv-U access to trusted networks where business requirements allow.
- Rotate potentially exposed secrets after remediation if encrypted sensitive values may have been disclosed.
- Monitor SolarWinds guidance for clarified affected versions, fixes, or compensating controls.
Validation and detection
- Confirm installed Serv-U FTP Server versions across production and backup systems.
- Check whether any instance reports version 15.3.0.
- Review logs and exposure points for disclosed encrypted Serv-U values.
- Verify network access controls limit who can reach Serv-U services.
- Document remediation status against SolarWinds advisory guidance.
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-798: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2021-35252 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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:N/UI:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3-2_release_notes.htmCVE reference
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35252CVE reference
- https://www.solarwinds.com/trust-center/security-advisories/CVE-2021-35252CVE reference
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.
Use of Hard-coded Credentials
Use of Hard-coded Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.