CVE-2019-16785
Waitress through version 1.3.1 implemented a "MAY" part of the RFC7230 which states: "Although the line terminator for the start-line and header fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Waitress through version 1.3.1 implemented a "MAY" part of the RFC7230 which states: "Although the line terminator for the start-line and header fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any preceding CR." Unfortunately if a front-end server does not parse header fields with an LF the same way as it does those with a CRLF it can lead to the front-end and the back-end server parsing the same HTTP message in two different ways. This can lead to a potential for HTTP request smuggling/splitting whereby Waitress may see two requests while the front-end server only sees a single HTTP message. This issue is fixed in Waitress 1.4.0.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 2.54% probability · 84th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- agendaless/waitress · oracle/communications cloud native core network function cloud native environment · debian/debian linux · fedoraproject/fedora · redhat/openstack
- Source
- security-advisories@github.com
References
- https://access.redhat.com/errata/RHSA-2020:0720Third Party Advisory
- https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixesVendor Advisory
- https://github.com/Pylons/waitress/commit/8eba394ad75deaf9e5cd15b78a3d16b12e6b0ebaPatch, Third Party Advisory
- https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57pExploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://access.redhat.com/errata/RHSA-2020:0720Third Party Advisory
- https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixesVendor Advisory
- https://github.com/Pylons/waitress/commit/8eba394ad75deaf9e5cd15b78a3d16b12e6b0ebaPatch, Third Party Advisory
- https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57pExploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.