Security readout for executives and security teams
Plain-English summary
CVE-2021-21805 is a critical flaw in Advantech R-SeeNet 2.4.12. A remote, unauthenticated attacker could send a crafted web request to the ping.php function and execute operating-system commands. That could allow full compromise of the server running R-SeeNet.
Executive priority
Handle as urgent for any affected deployment. The vulnerability can allow unauthenticated remote command execution with full system impact, but the supplied evidence does not confirm active exploitation or provide a named patch.
Technical view
The CVE describes CWE-78 OS command injection in ping.php in Advantech R-SeeNet 2.4.12 (20.10.2020). The CVSS 3.0 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating network reachability, low attack complexity, no privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to organizations running Advantech R-SeeNet 2.4.12, especially where its web interface is reachable from untrusted networks. The source bundle does not identify other affected versions, deployment patterns, or internet exposure data.
Exploitation context
The source bundle says a specially crafted HTTP request can trigger arbitrary OS command execution. CISA KEV status is false in the provided data, and no cited source in the bundle states active exploitation. Treat this as high-impact and remotely reachable, but not confirmed exploited from the supplied evidence.
Researcher notes
Focus validation on exact product/version matching, web exposure, and evidence of command execution from ping.php activity. Avoid assuming broader Advantech product impact because the bundle only names R-SeeNet 2.4.12 (20.10.2020).
Mitigation direction
- Inventory systems running Advantech R-SeeNet and confirm whether version 2.4.12 is present.
- Restrict R-SeeNet web access to trusted administration networks only.
- Check Advantech and Talos guidance for fixed versions or vendor-approved mitigations.
- Monitor web logs for unusual access to ping.php.
- Prioritize replacement or isolation if vendor fixes are unavailable.
Validation and detection
- Confirm R-SeeNet version from asset records or administrative interfaces.
- Identify whether the R-SeeNet web interface is reachable from untrusted networks.
- Review HTTP logs for unexpected requests to ping.php.
- Check host logs for suspicious child processes spawned by the web service.
- Document compensating controls and vendor guidance status.
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-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. 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 lookupExecution 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-2021-21805 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
- Critical
- CVSS
- 9.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
9.8CriticalVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1274CVE 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 Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.