Security readout for executives and security teams
Plain-English summary
This is a moderate web-cache manipulation issue in WirelessHART gateway products. A remote attacker could cause cached pages to contain rewritten links or URLs. The published score is 5.4 because exploitation is network reachable but requires user interaction and has limited confidentiality and integrity impact.
Executive priority
Treat this as a targeted operational-technology hygiene issue, not an emergency. Prioritize exposed or remotely administered gateways, then follow vendor guidance and reduce web-interface reachability.
Technical view
CVE-2021-34559 affects WirelessHART-Gateway firmware up to 3.0.8, including listed Phoenix Contact WHA-GW-F2D2 variants. The record maps to CWE-444 and describes remote rewriting of links and URLs in cached pages to arbitrary strings. CVSS v3.1 is AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
Likely exposure
Exposure is most relevant where affected WirelessHART gateway web or management interfaces are reachable from untrusted networks, shared operational networks, or user browsing paths that could interact with cached pages.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. The CVSS vector indicates no privileges are required, attack complexity is low, and user interaction is required.
Researcher notes
Evidence is limited to the CVE description, CVSS vector, affected product list, and VDE advisory reference. The bundle contains a vendor-name inconsistency between PEPPERL+FUCHS in the description and Phoenix Contact in affected products; validate against the advisory before scoping broadly.
Mitigation direction
- Inventory WirelessHART gateways and identify firmware versions at or below 3.0.8.
- Check the VDE/vendor advisory for supported firmware updates or official mitigations.
- Restrict gateway web management access to trusted administration networks.
- Use VPN, firewall rules, or allowlists for remote management exposure.
- Review proxy or cache configurations affecting gateway management pages.
Validation and detection
- Confirm whether listed WHA-GW-F2D2 product variants exist in the environment.
- Record each gateway firmware version and compare against 3.0.8 or below.
- Verify management interfaces are not internet reachable.
- Inspect cached management pages for unexpected rewritten links or URLs.
- Review access logs for unusual remote interaction with gateway web pages.
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-444: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2021-34559 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
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/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:R/S:U/C:L/I:L/A:N2.82.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en-us/advisories/vde-2021-027CVE reference · x_refsource_CONFIRM
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.
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.