Inconsistent interpretation of HTTP requests in waitress
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2019-16786 |
| CWE-ID | CWE-444 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
waitress Other software / Other software solutions |
| Vendor | Pylons Project |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
1) Inconsistent interpretation of HTTP requests
EUVDB-ID: #VU30507
Risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2019-16786
CWE-ID:
CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to manipulate data.
Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: "Transfer-Encoding: gzip, chunked" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.
MitigationInstall update from vendor's website.
Vulnerable software versionswaitress: 1.3.0
External linkshttp://access.redhat.com/errata/RHSA-2020:0720
http://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
http://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3
http://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
