CVE-2021-32066
Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.91%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack."
- CVSS 3.1
- 7.4 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 2.91% probability · 86th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-755
- Affected
- ruby-lang/ruby · oracle/jd edwards enterpriseone tools
- Source
- cve@mitre.org
References
- https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922aPatch, Third Party Advisory
- https://hackerone.com/reports/1178562Exploit, Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.htmlThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20210902-0004/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/Vendor Advisory
- https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922aPatch, Third Party Advisory
- https://hackerone.com/reports/1178562Exploit, Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.htmlThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20210902-0004/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.