Security readout for executives and security teams
Plain-English summary
CVE-2021-43159 is a reported remote code execution issue in Ruijie Networks RG-EW Series routers running affected ReyeeOS/EW firmware. In business terms, a vulnerable router could become an entry point for takeover if its management interface is reachable by an attacker.
Executive priority
Prioritize any affected router exposed to untrusted networks. If exposure is internal only, handle through the next urgent network maintenance window while restricting management access immediately.
Technical view
The CVE describes RCE through the setSessionTime function in /cgi-bin/luci/api/common on Ruijie RG-EW Series routers up to ReyeeOS 1.55.1915 / EW_3.0(1)B11P55. The public CVE data does not include CVSS, CWE, or complete structured affected-product records.
Likely exposure
Organizations using Ruijie RG-EW Series routers on the listed firmware are potentially exposed. Risk is higher where router web management or API access is reachable from the internet, guest networks, or other untrusted segments.
Exploitation context
A public Full Disclosure reference exists, but the provided sources do not show CISA KEV listing or confirmed active exploitation. Treat internet-exposed management interfaces as urgent because the reported impact is remote code execution.
Researcher notes
Evidence is incomplete: CVE records name the vulnerable function and firmware boundary, but lack CVSS, CWE, vendor advisory details, and structured CPE data. Use the description and linked disclosure to guide asset validation, then confirm fixes with Ruijie.
Mitigation direction
- Check Ruijie guidance for fixed firmware or supported remediation.
- Upgrade affected routers if a vendor-supported firmware is available.
- Restrict router management access to trusted admin networks only.
- Disable remote management if it is not required.
- Replace unsupported devices if no vendor fix is available.
Validation and detection
- Inventory Ruijie RG-EW routers and record firmware versions.
- Identify devices running ReyeeOS 1.55.1915 / EW_3.0(1)B11P55 or earlier.
- Confirm whether management interfaces are internet-accessible.
- Review logs for unexpected access to /cgi-bin/luci/api/common.
- Verify remediation against current vendor documentation.
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.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-43159 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://seclists.org/fulldisclosure/2022/May/0CVE reference, mitre
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.