GHSA-674j-7m97-j2p9
CRITICALcurl FTP path confusion leads to NIL byte out of bounds write
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
curlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
curl can be coerced into writing a zero byte out of bounds.
This bug can trigger when curl is told to work on an FTP URL, with the setting to only issue a single CWD command (--ftp-method singlecwd or the libcurl alternative CURLOPT_FTP_FILEMETHOD).
curl then URL-decodes the given path, calls strlen() on the result and deducts the length of the file name part to find the end of the directory within the buffer. It then writes a zero byte on that index, in a buffer allocated on the heap.
If the directory part of the URL contains a %00 sequence, the directory length might end up shorter than the file name path, making the calculation size_t index = directory_len - filepart_len end up with a huge index variable for where the zero byte gets stored: heap_buffer[index] = 0. On several architectures that huge index will wrap and work as a negative value, thus overwriting memory before the intended heap buffer.
By using different file part lengths and putting the string %00 in different places in the URL, an attacker that can control what paths a curl-using application uses can write that zero byte on different indexes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | curl | ≥ 7.12.3 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for curl. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of curl has shipped for GHSA-674j-7m97-j2p9 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-674j-7m97-j2p9 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-674j-7m97-j2p9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-674j-7m97-j2p9 in your dependencies?
O3 detects GHSA-674j-7m97-j2p9 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.