Security readout for executives and security teams
Plain-English summary
This CVE describes remote arbitrary code execution on Quectel EG25-G modem devices through firmware build 202006130814. The issue is tied to unsafe handling of AT command input in the modem forwarding daemon. Business urgency depends on whether affected modems are present and whether their AT command interface is reachable from remote or semi-trusted paths.
Executive priority
Treat as a high-priority inventory and vendor-remediation issue for connected products using EG25-G modems. Prioritize externally managed or remotely reachable deployments first.
Technical view
The CVE states that shell metacharacters in quectel_handle_fumo_cfg input can be passed through atfwd_daemon, allowing arbitrary code execution. The provided sources identify Quectel EG25-G devices through 202006130814, but do not provide CVSS, CWE classification, a named patch, or broad affected-product mapping.
Likely exposure
Exposure is most likely in products or fleets containing Quectel EG25-G modems on firmware through 202006130814. Risk is higher where host software, remote management, or exposed services can send AT commands to the modem.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Public technical discussion exists, and the CVE describes remote code execution, but operational exploit prevalence is not established in the provided evidence.
Researcher notes
Evidence is limited to the CVE record and referenced public research. No CVSS, CWE, official patch details, or KEV status are provided. Avoid assuming impact beyond EG25-G devices through 202006130814 unless vendor data confirms it.
Mitigation direction
- Inventory assets using Quectel EG25-G modems and record firmware versions.
- Check Quectel or device-vendor guidance for firmware newer than 202006130814.
- Restrict AT command access to trusted local processes only.
- Remove remote exposure of modem control or management interfaces.
- Monitor vendor advisories and retest after firmware updates.
Validation and detection
- Confirm whether deployed hardware contains Quectel EG25-G modems.
- Verify firmware build is later than 202006130814 where possible.
- Map services or applications that can send AT commands.
- Check whether remote management paths can reach modem control functions.
- Review logs for unexpected modem management or FUMO configuration activity.
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-2021-31698 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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://nns.ee/blog/2021/04/03/modem-rce.htmlCVE 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.