HTTP Request Smuggling: Content-Length Sent Twice in Waitress
Published Jan 22, 2020
7.5
HIGHCVSS 3.1
EPSS 1.98%
Description
Waitress through version 1.3.1 allows request smuggling by sending the Content-Length header twice. Waitress would header fold a double Content-Length header and due to being unable to cast the now comma separated value to an integer would set the Content-Length to 0 internally. If two Content-Length headers are sent in a single request, Waitress would treat the request as having no body, thereby treating the body of the request as a new request in HTTP pipelining. This issue is fixed in Waitress 1.4.0.
Affected products
-
- Version <= 1.3.1StatusaffectedConstraints<=1.3.1
- Version
Configuration 1
- ≤ 1.3.1
Configuration 2
- 1.10.0
Configuration 3
- 9.0
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
1 other source (GitHub) ▾
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v5
Table of values (17 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.98% (0.01984) | 79.83th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.12% (0.02122) | 79.42th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.19% (0.00192) | 57.01th | v3 (v2023.03.01) |
| May 17, 2024 | 0.19% (0.00192) | 56.37th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.27% (0.00272) | 67.04th | v3 (v2023.03.01) |
| Nov 26, 2023 | 0.27% (0.00272) | 64.45th | v3 (v2023.03.01) |
| Nov 11, 2023 | 0.28% (0.00281) | 64.95th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.24% (0.00235) | 59.71th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Sep 29, 2022 | 1.02% (0.01018) | 39.10th | v2 (v2022.01.01) |
| Apr 20, 2022 | 1.02% (0.01018) | 37.10th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.95% (0.00954) | 32.50th | v2 (v2022.01.01) |
| Feb 4, 2022 | 5.74% (0.05736) | 77.22th | v2 (v2022.01.01) |
| Feb 3, 2022 | 3.63% (0.03630) | 71.73th | v1 |
| Jan 6, 2022 | 3.63% (0.03630) | 71.48th | v1 |
| Sep 1, 2021 | 0.83% (0.00833) | 57.50th | v1 |
| Apr 14, 2021 | 0.83% (0.00833) | 0.00th | v1 |
References (8)
- https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes x_refsource_MISCRelease Notes
- https://github.com/Pylons/waitress/commit/575994cd42e83fd772a5f7ec98b2c56751bd3f65 x_refsource_MISCPatch
- https://github.com/Pylons/waitress/security/advisories/GHSA-4ppp-gpcr-7qf6 x_refsource_CONFIRMThird Party Advisory
- https://github.com/advisories/GHSA-4ppp-gpcr-7qf6 Advisory
- https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2020-178.yaml
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2019-16792
- https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISCPatchThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes | x_refsource_MISCRelease Notes | |
| https://github.com/Pylons/waitress/commit/575994cd42e83fd772a5f7ec98b2c56751bd3f65 | x_refsource_MISCPatch | |
| https://github.com/Pylons/waitress/security/advisories/GHSA-4ppp-gpcr-7qf6 | x_refsource_CONFIRMThird Party Advisory | |
| https://github.com/advisories/GHSA-4ppp-gpcr-7qf6 | Advisory | |
| https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2020-178.yaml | ||
| https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2019-16792 | ||
| https://www.oracle.com/security-alerts/cpuapr2022.html | x_refsource_MISCPatchThird Party Advisory |
Change history (0)
No recorded changes yet.