Cyber Resilience

CVE-2026-42167

SQLi in Proftpd ≤ 1.3.9b

Public PoCSQLi
Published
28 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.043 90th percentile
Risk Priority 69 floored blend · peak EPSS

Summary

CVE-2026-42167 is a high-severity SQL Injection (CWE-89) vulnerability in Proftpd Proftpd. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 10% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

mod_sql in ProFTPD versions before 1.3.9a is vulnerable to SQL injection that permits remote code execution. The flaw is triggered when USER command logging is configured with an expansion such as %U and the SQL backend permits execution of commands such as COPY TO PROGRAM, allowing an attacker-supplied username to be interpreted as SQL.

Remote attackers without authentication can exploit the issue by sending a crafted username during FTP authentication. Successful exploitation grants arbitrary code execution on the server when the logging and backend conditions are present, corresponding to the CVSS 8.1 rating that reflects high impact across confidentiality, integrity, and availability.

Advisories and patches referenced in the ProFTPD 1.3.10rc1 release notes, the project issue tracker, and oss-security postings indicate that the defect is resolved by upgrading to version 1.3.9a or later; operators are advised to review mod_sql logging configurations and restrict SQL backend privileges as interim controls.

EPSS rose from a low baseline to a peak of 0.1239 on 2026-05-01 before receding to the current value of 0.0699, indicating increased exploitation interest shortly after disclosure. Public proof-of-concept code and detailed analysis have also been published.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

mod_sql in ProFTPD before 1.3.9a allows remote attackers to execute arbitrary code via a username, in scenarios where there is logging of USER requests with an expansion such as %U, and the SQL backend allows commands (e.g., COPY TO PROGRAM).

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-26034Shared CWE-89
CVE-2023-46914Shared CWE-89
CVE-2023-44284Shared CWE-89
CVE-2023-48722Shared CWE-89
CVE-2024-4071Shared CWE-89
CVE-2023-49085Shared CWE-89
CVE-2024-25314Shared CWE-89
CVE-2024-0528Shared CWE-89
CVE-2024-8167Shared CWE-89
CVE-2023-7142Shared CWE-89

Affected Assets

proftpd
proftpd
≤ 1.3.9b

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V6.2.5

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover SQLi flaws before deployment but does not stop their introduction.

Input validation directly stops untrusted data from reaching SQL query construction without neutralization.

Secure engineering principles require parameterized queries and input sanitization that structurally eliminate SQLi.

System monitoring can identify attempted SQLi exploitation via anomalous queries after the weakness exists.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target injection flaws during coding and review so largely prevent CWE-89 introduction, yet the single broad outcome leaves residual risk from incomplete neutralization techniques or missed edge cases.

PR.AT-02 partial match
prevents

Training raises developer awareness of SQLi risks and can reduce introduction likelihood (partial) but removes none of the actual coding flaw's risk by itself since technical neutralization is still required.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

The same secure-coding and static-analysis activities surface missing neutralization of SQL metacharacters before the system is accepted.

prevents

Early warnings and shared best-practice information help organizations apply the latest remediation techniques against SQL-injection vulnerabilities.

prevents

Threat-intelligence feeds that surface new SQL-injection campaigns enable rapid updates to query-construction defenses and detection signatures before exploitation occurs.

prevents

Secure-coding rules and security testing phases mandate the use of parameterized queries or equivalent escaping, preventing the construction of dynamic SQL statements from untrusted input.

prevents

Language-specific secure coding rules, peer review and SAST together prevent the construction of SQL statements from untrusted data without proper parameterization or escaping.

References