7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
0.014 Low
EPSS
Percentile
85.9%
If an application using Puma allows untrusted input in an early-hints header, an attacker can use a carriage return character to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting.
While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS).
This is related to CVE-2020-5247, which fixed this vulnerability but only for regular responses.
This has been fixed in 4.3.3 and 3.12.4.
Users can not allow untrusted/user input in the Early Hints response header.
If you have any questions or comments about this advisory:
github.com/puma/puma
github.com/puma/puma/commit/c22712fc93284a45a93f9ad7023888f3a65524f3
github.com/puma/puma/security/advisories/GHSA-33vf-4xgg-9r58
github.com/puma/puma/security/advisories/GHSA-84j7-475p-hp8v
github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2020-5249.yml
lists.fedoraproject.org/archives/list/[email protected]/message/BMJ3CGZ3DLBJ5WUUKMI5ZFXFJQMXJZIK
lists.fedoraproject.org/archives/list/[email protected]/message/DIHVO3CQMU7BZC7FCTSRJ33YDNS3GFPK
lists.fedoraproject.org/archives/list/[email protected]/message/NJ3LL5F5QADB6LM46GXZETREAKZMQNRD
nvd.nist.gov/vuln/detail/CVE-2020-5249
owasp.org/www-community/attacks/HTTP_Response_Splitting
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
0.014 Low
EPSS
Percentile
85.9%