CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
AI Score
Confidence
Low
EPSS
Percentile
17.7%
Clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-Forwarded_For). Any users trusting headers set by their proxy may be affected. Attackers may be able to downgrade connections to HTTP (non-SSL) or redirect responses, which could cause confidentiality leaks if combined with a separate MITM attack.
v6.4.3/v5.6.9 now discards any headers using underscores if the non-underscore version also exists. Effectively, allowing the proxy defined headers to always win.
Nginx has a underscores_in_headers configuration variable to discard these headers at the proxy level.
Any users that are implicitly trusting the proxy defined headers for security or availability should immediately cease doing so until upgraded to the fixed versions.
github.com/advisories/GHSA-9hf4-67fc-4vf4
github.com/puma/puma/commit/cac3fd18cf29ed43719ff5d52d9cfec215f0a043
github.com/puma/puma/commit/f196b23be24712fb8fb16051cc124798cc84f70e
github.com/puma/puma/security/advisories/GHSA-9hf4-67fc-4vf4
github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2024-45614.yml
nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers
nvd.nist.gov/vuln/detail/CVE-2024-45614
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
AI Score
Confidence
Low
EPSS
Percentile
17.7%