Vulnerability in Puma
CVE-2020-11077
In Puma (RubyGem) before 4.3.5 and 3.12.6, a client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. If the proxy uses persistent connections and the client adds another request in via HTTP pipelining, the proxy may mistake it as the first request's body. Puma, however, would see it as two requests, and when processing the second request, send back a response that the proxy does not expect. If the proxy has reused the persistent connection to Puma to send another request for a different client, the second response from the first client will be sent to the second client. This is a similar but different vulnerability from CVE-2020-11076. The problem has been fixed in Puma 3.12.6 and Puma 4.3.5.
Vulnerability class: HTTP Request Smuggling
EPSS: 0.028 (85.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N.
Affected products
- Puma — versions < 3.12.6, >= 4.0.0, < 4.3.5
- Debian Debian_linux — versions 9.0
- Fedoraproject Fedora — versions 33
- Opensuse Leap — versions 15.1, 15.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (vendor-advisory, Mailing List, Third Party Advisory, x_refsource_SUSE)
- security-advisories@github.com (vendor-advisory, Mailing List, Third Party Advisory, x_refsource_SUSE)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory)
- security-advisories@github.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-11077?
- CVE-2020-11077 is a medium-severity vulnerability in Puma, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 6.8/10. Published 2020-05-22.
- How severe is CVE-2020-11077?
- Medium severity. CVSS v3 base score is 6.8 out of 10.
- Is CVE-2020-11077 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.