CVE-2019-16792: HTTP Request Smuggling: Content-Length Sent Twice in Waitress
Vulnerability summary
CVE-2019-16792 is a high (CVSS 7.5) vulnerability in agendaless waitress. EPSS estimates a 1.98% chance of exploitation in the next 30 days, higher than 80.6% of scored vulnerabilities.
Not severe (CVSS 7.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 8 · Related 7Timeline
- 22-01-2020PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA7.1HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:NDiffers
- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
1.98%
Chance of exploitation in the next 30 days
Percentile
81%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.98% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- waitress< 1.4.1-1
- debian_linuxEOL9.0
Agendaless1 product
- waitress≤ 1.3.1
Oracle1 product
Pylons1 product
- waitress≥ <= 1.3.1, ≤ 1.3.1
PyPI1 product
- waitress< 575994cd42e83fd772a5f7ec98b2c56751bd3f65 | < 1.4.0
Ubuntu1 product
- waitressAll versions (No fix recorded)
6 vendors · 7 products
References
12 links- github.com/Pylons/waitress/security/advisories/GHSA-4ppp-gpcr-7qf6X Refsource CONFIRMThird Party AdvisoryWEBAdvisoryREPORT
- github.com/Pylons/waitress/commit/575994cd42e83fd772a5f7ec98b2c56751bd3f65X Refsource MISCPatchWEBFIX
lists.debian.org/debian-lts-announce/2022/05/msg00011.htmlMailing ListX Refsource MLISTThird Party AdvisoryWEB
- github.com/Pylons/waitressPACKAGE