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Fencer Intel
medium 6.1

CVE-2015-9096 json

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 demonstrate…

published 9y ago modified 4mo ago also EUVD-2015-8950

cvss
6.1
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.7%
EPSS 3.7% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

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.

Patch / fix

  • ruby2.0 Ubuntu 14.04 LTS 2.0.0.484-1ubuntu2.4
  • ruby2.3 Ubuntu 16.04 LTS 2.3.1-2~16.04.2
  • ruby1.9.1 Ubuntu 14.04 LTS 1.9.3.484-2ubuntu1.3

ubuntu advisories UBUNTU-CVE-2015-9096

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ruby4.0 hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-libs hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-bundled-gems hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-default-gems hummingbird 1 4.0.0-33.3.hum1
  • ruby3.3 hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-libs hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-bundled-gems hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-default-gems hummingbird 1 3.3.10-23.1.hum1

red hat advisories RHSA-2026:8838RHSA-2026:7305RHSA-2026:7307

  • ruby2.1 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +14 more 2.1.9-19.3.2
  • yast2-ruby-bindings SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 3.1.53-9.8.1

suse advisories SUSE-SU-2020:1570-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-9096 updated cvss 5.3

ruby: SMTP command injection via CRLF sequences in RCPT TO or MAIL FROM commands in Net::SMTP

  • Red Hat CloudForms Management Engine 5 ruby-200-ruby, rh-ruby22-ruby Red Hat Enterprise Linux 5 ruby Red Hat Enterprise Linux 6 ruby, ruby-ri, ruby-irb, ruby-libs, ruby-rdoc, ruby-tcltk Red Hat Enterprise Linux 7 ruby, ruby-irb, rubygems, ruby-libs, ruby-tcltk, rubygem-json, +6 more Red Hat Software Collections rh-ruby22-ruby, rh-ruby23-ruby, rh-ruby22-ruby-irb, rh-ruby22-rubygems, rh-ruby23-ruby-irb, rh-ruby23-rubygems, +24 more Red Hat Subscription Asset Manager ruby193-ruby
    affected: no fix planned “Will not fix”
  • Red Hat Hardened Images ruby3.4 3.4.8-31.1.hum1, ruby4.0 4.0.0-33.3.hum1, ruby3.3 3.3.10-23.1.hum1, ruby3.4-libs 3.4.8-31.1.hum1, ruby4.0-libs 4.0.0-33.3.hum1, ruby3.3-libs 3.3.10-23.1.hum1, +6 more
    fixed: vendor fix RHSA-2026:7305
  • Red Hat Hardened Images rubygem3.3-rbs 3.4.0-23.1.hum1, rubygem3.3-rss 0.3.1-23.1.hum1, rubygem3.4-rbs 3.8.0-31.1.hum1, rubygem3.4-rss 0.3.1-31.1.hum1, rubygem4.0-rss 0.3.2-33.3.hum1, rubygem3.3-irb 1.13.1-23.1.hum1, +45 more Red Hat Software Collections rh-ruby24-ruby, rh-ruby24-ruby-irb, rh-ruby24-rubygems, rh-ruby24-ruby-libs, rh-ruby24-rubygem-json, rh-ruby24-rubygem-rake, +11 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.69% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • mbsd.jp http://www.mbsd.jp/Whitepaper/smtpi.pdf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 6.1 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-93 Improper Neutralization of CRLF Sequences

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.