CRLF injection vulnerability in the redirect function in url_helper.php in CodeIgniter 1.5.3 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in an unspecified parameter, as demonstrated by a Set-Cookie header.
Conclusion & alert: CVE-2007-3709 is rated Moderate Risk (43.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.19%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.38% | 1.19% | +0.81% |
| 2 | 2026-02-27 | 0.31% | 0.38% | +0.07% |
| 3 | 2025-03-30 | — | 0.31% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| codeigniter | codeigniter | 1.5.3 | cpe:2.3:a:codeigniter:codeigniter:1.5.3:*:*:*:*:*:*:* |