CVE-2018-1000164
CVE-2018-1000164 is a high-severity vulnerability in Gunicorn with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-93.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 2% (82nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-93
- Affected product: Gunicorn
- Published:
- Last modified:
Description
gunicorn version 19.4.5 contains a CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers vulnerability in "process_headers" function in "gunicorn/http/wsgi.py" that can result in an attacker causing the server to return arbitrary HTTP headers. This vulnerability appears to have been fixed in 19.5.0.
Frequently asked questions
- What is CVE-2018-1000164?
- gunicorn version 19.4.5 contains a CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers vulnerability in "process_headers" function in "gunicorn/http/wsgi.py" that can result in an attacker causing the server to return arbitrary HTTP headers. This vulnerability appears to have been fixed in 19.5.0.
- How severe is CVE-2018-1000164?
- CVE-2018-1000164 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
- Is CVE-2018-1000164 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2018-1000164?
- CVE-2018-1000164 primarily affects Gunicorn. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2018-1000164?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2018-1000164 published?
- CVE-2018-1000164 was published on 2018-04-18 and last updated on 2026-06-17.
References
- https://epadillas.github.io/2018/04/02/http-header-splitting-in-gunicorn-19.4.5
- https://github.com/benoitc/gunicorn/issues/1227
- https://lists.debian.org/debian-lts-announce/2018/04/msg00022.html
- https://usn.ubuntu.com/4022-1/
- https://www.debian.org/security/2018/dsa-4186
Affected products (3)
- cpe:2.3:a:gunicorn:gunicorn:19.4.5:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
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