CVE-2007-3709
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCRLF 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceCodeIgniter 1.5.3 contains a CRLF injection vulnerability in the redirect() function of url_helper.php. The function fails to sanitize user-supplied input, allowing remote attackers to inject arbitrary HTTP headers (such as Set-Cookie) via CRLF sequences (\r\n), potentially enabling HTTP response splitting attacks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 1.5.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- None
- Integrity
- Partial
- Availability
- None
AV:N/AC:L/Au:N/C:N/I:P/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify CodeIgniter versionCheck the VERSION file in the system directory, or look for a version constant in system/CodeIgniter.php. Typical paths: system/CodeIgniter.php or system/core/CodeIgniter.phpAffected if The installed version is exactly 1.5.3
-
Locate the vulnerable url_helper.php fileFind url_helper.php in the system/helpers/ or application/helpers/ directory. The redirect() function is defined in this file.Affected if The file exists and contains a redirect() function that processes URL parameters
-
Inspect the redirect() function for input sanitizationOpen url_helper.php and examine the redirect() function definition. Look for any code that filters or removes \r and \n characters from the $url parameter before using it in header() calls.Affected if The redirect() function lacks CRLF sanitization - it directly passes user input to header() without stripping \r\n sequences
-
Determine if redirect() uses user-supplied inputSearch your codebase for calls to redirect() that pass $_GET, $_POST, or other user-controlled variables directly, such as redirect($this->input->get('url')) or redirect($_REQUEST['next'])Affected if The application passes unsanitized user input to redirect() from query strings, form inputs, or other HTTP request data
You are affected if running CodeIgniter 1.5.3 with the redirect() function in url_helper.php that lacks CRLF sanitization and is called with user-supplied input.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataSanitize all input passed to the redirect() function to remove or encode CRLF sequences. Implement input validation that rejects or strips \r and \n characters from parameters used in HTTP header generation.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2007-3709 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2007-3709 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data