CVE-2020-5247
HTTP Response Splitting in Puma
Public exploit available. Not confirmed exploited in the wild yet. Fixed in 3.12.4.
What to do
Find your product and version, then upgrade to the build on the right.
- PumaAffected: < 3.12.3Upgrade to: not statedAffected: >= 4.0.0, < 4.3.2Upgrade to: not statedStated by: CVE record
- RubyGems pumaAffected: < 3.12.4Upgrade to: 3.12.4Stated by: GitHub advisory
- Ruby-lang RubyAffected: ≤ 2.3.0Upgrade to: after 2.3.0Stated by: NVD
- Fedora Project FedoraAffected: 30Upgrade to: not statedStated by: BDU
- Сообщество свободного программного обеспечения PumaAffected: до 4.3.2Upgrade to: not statedStated by: BDU
Versions as the sources state them. 1 more product has version data. Full version matrix after sign-in
What it is
From the CVE record
In Puma (RubyGem) before 4.3.2 and before 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. `CR`, `LF` or`/r`, `/n`) 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-2019-16254, which fixed this vulnerability for the WEBrick Ruby web server. This has been fixed in versions 4.3.2 and 3.12.3 by checking all headers for line endings and rejecting headers with those characters.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
1 source with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
2.5% chance of exploitation activity in the next 30 days, which ranks it in the 85th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
The patch came 471 days before any public exploit.
- OpenVAS check added
- Public exploit / PoCsource: github-poc
- Patch availableworkaround available, record updated
- Publishedweakness classified, att&ck mapped
Affected products
And 3 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Scored 6.5 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality LowSome restricted information is disclosed, but limited in scope
- Integrity LowData modification is possible but limited in scope or consequence
- Availability LowReduced performance or intermittent disruption of service
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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