Security readout for executives and security teams
Plain-English summary
This is a critical flaw in BQE BillQuick Web Suite that let unauthenticated attackers break into vulnerable systems through SQL injection. Public sources say it was exploited in the wild in October 2021 to install ransomware, so exposed legacy deployments should be treated as high-risk until verified patched and investigated.
Executive priority
Treat this as an urgent remediation and incident-review item for any remaining BillQuick Web Suite deployment. The combination of unauthenticated access, remote code execution, ransomware use, and CISA KEV listing makes business impact potentially severe.
Technical view
CVE-2021-42258 is an unauthenticated SQL injection in BQE BillQuick Web Suite 2018 through 2021 before 22.0.9.1. The CVE states exploitation can lead to remote code execution, including code execution through SQL Server xp_cmdshell as MSSQLSERVER$. CVSS is 9.8 and CWE-89 applies.
Likely exposure
Exposure is most likely where BQE BillQuick Web Suite 2018, 2019, 2020, or 2021 is still deployed below version 22.0.9.1, especially if reachable from the internet. The provided sources do not include CPEs or a complete affected-build inventory.
Exploitation context
Active exploitation is supported by CISA KEV and the Huntress advisory. The CVE description says exploitation occurred in October 2021 for ransomware installation. The bundle identifies the txtID, also called username, parameter as one example of the vulnerable input.
Researcher notes
Evidence supports unauthenticated SQL injection leading to remote code execution, with ransomware exploitation reported. The source bundle names affected major versions and the fixed threshold, but does not provide a complete product matrix, vulnerable build list, or official vendor advisory URL.
Mitigation direction
- Upgrade BillQuick Web Suite to version 22.0.9.1 or later.
- Check BQE vendor guidance for any additional hardening or cleanup instructions.
- Remove public internet exposure until patched and validated.
- Investigate affected hosts for ransomware, web shell, and SQL Server compromise indicators.
- Review SQL Server configuration and disable risky execution paths where operationally feasible.
Validation and detection
- Inventory all BillQuick Web Suite deployments and record exact versions.
- Confirm no deployment remains below version 22.0.9.1.
- Identify whether any BillQuick Web Suite instance is internet-facing.
- Review web and SQL logs for suspicious username or txtID activity.
- Check EDR and backup systems for ransomware-related alerts or failures.
Public sources used
Michael Williams reviewed this cited source version on .
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-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. 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 lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-42258 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 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/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.
CISA KEV status
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:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/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://www.huntress.com/blog/threat-advisory-hackers-are-exploiting-a-vulnerability-in-popular-billing-software-to-deploy-ransomwareCVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42258CVE reference · government-resource
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 SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.