Skip to content
Noroxi
CVE-2015-9096· NVD / CVE Program· CNA mitre

Net::SMTP in Ruby before 2.4.0 is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated

Net::SMTP in Ruby before 2.4.0 is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substring.

MediumCVSS 6.1 · v3.0—No exploit Fix available
Published
Jun 12, 2017
Updated
Jun 16, 2026
EPSS
3.7% · 89th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

25

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.7%

Affected systems

VendorProduct
ruby-langruby

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • ruby-lang rubyup to 2.4.0 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:8ruby2.1before 2.1.5-2+deb8u42.1.5-2+deb8u4
Debian:9ruby2.3before 2.3.3-1+deb9u12.3.3-1+deb9u1
SUSE:HPE Helion OpenStack 8ruby2.1before 2.1.9-19.3.22.1.9-19.3.2
SUSE:OpenStack Cloud 7yast2-ruby-bindingsbefore 3.1.53-9.8.13.1.53-9.8.1

Same product

ruby-lang: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-17405Ruby before 2.4.3 allows Net::FTP command injection.
    57Plan
  • CVE-2008-3656Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick i
    52Plan
  • CVE-2021-28966In Ruby through 3.0 on Windows, a remote attacker can submit a crafted path when a Web application handles a parameter with TmpDir.
    47Plan
  • CVE-2017-14064Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can expose arbitrary memory during a JSON.generate call.
    42Plan
  • CVE-2017-17790The lazy_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demons
    41Plan
  • CVE-2016-2339An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby.
    41Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:ruby2.12.1.5-2+deb8u4 · Debian:8Package registry (OSV)
debian:ruby2.32.3.3-1+deb9u1 · Debian:9Package registry (OSV)
suse:ruby2.12.1.9-19.3.2 · SUSE:HPE Helion OpenStack 8Package registry (OSV)
suse:yast2-ruby-bindings3.1.53-9.8.1 · SUSE:OpenStack Cloud 7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records