7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.6 High
AI Score
Confidence
High
0.02 Low
EPSS
Percentile
88.8%
Puma is a concurrent HTTP 1.1 server for Ruby/Rack applications. The fix for CVE-2019-16770 was incomplete. The original fix only protected existing connections that had already been accepted from having their requests starved by greedy persistent-connections saturating all threads in the same process. However, new connections may still be starved by greedy persistent-connections saturating all threads in all processes in the cluster. A puma
server which received more concurrent keep-alive
connections than the server had threads in its threadpool would service only a subset of connections, denying service to the unserved connections. This problem has been fixed in puma
4.3.8 and 5.3.1. Setting queue_requests false
also fixes the issue. This is not advised when using puma
without a reverse proxy, such as nginx
or apache
, because you will open yourself to slow client attacks (e.g. slowloris). The fix is very small and a git patch is available for those using unsupported versions of Puma.
[
{
"product": "puma",
"vendor": "puma",
"versions": [
{
"status": "affected",
"version": "< 4.3.8"
},
{
"status": "affected",
"version": ">= 5.0.0, < 5.3.1"
}
]
}
]
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.6 High
AI Score
Confidence
High
0.02 Low
EPSS
Percentile
88.8%