CVE-2019-167857.1HighCWE-444

CVE-2019-16785: HTTP Request Smuggling: LF vs CRLF handling in Waitress

Pylons · Waitress

Vendor fix available · Affected: Pylons Waitress · Exploitation: possible (1 to 10%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

2.5%probability of exploitation in the next 30 days

85th percentile

050100

Higher than 85% of scored CVEs

7.1HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Pylons · Waitressfrom <= 1.3.1 up to and including 1.3.1

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Possible (1 to 10%). EPSS between 1% and 10%.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Inconsistent Interpretation of HTTP Requests · Injection and Smuggling
Vendor: Pylons
Published: December 2019
Band: Possible (1 to 10%), December 2019

CoverageNo articles yet

No CyberSIXT article names CVE-2019-16785 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.