CVE-2020-15917
CVE-2020-15917 is a critical-severity vulnerability in Claws-mail with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 7.5
- EPSS exploit prediction: 3% (83rd percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Claws-mail
- Published:
- Last modified:
Description
common/session.c in Claws Mail before 3.17.6 has a protocol violation because suffix data after STARTTLS is mishandled.
Frequently asked questions
- What is CVE-2020-15917?
- common/session.c in Claws Mail before 3.17.6 has a protocol violation because suffix data after STARTTLS is mishandled.
- How severe is CVE-2020-15917?
- CVE-2020-15917 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2020-15917 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-15917?
- CVE-2020-15917 primarily affects Claws-mail. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-15917?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2020-15917 published?
- CVE-2020-15917 was published on 2020-07-23 and last updated on 2026-06-17.
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00090.html
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00002.html
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00060.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00051.html
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00013.html
- https://git.claws-mail.org/?p=claws.git%3Ba=blob%3Bf=RELEASE_NOTES
- https://git.claws-mail.org/?p=claws.git%3Ba=commit%3Bh=fcc25329049b6f9bd8d890f1197ed61eb12e14d5
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6YVQB7NRBHO67Q74RS7RZCMW4ENRVBB4/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/G7UX65342HRVDQML4G4GEVEUB764EUM5/
- https://security.gentoo.org/glsa/202007-56
Affected products (7)
- cpe:2.3:a:claws-mail:claws-mail:*:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
- cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:*
- cpe:2.3:a:opensuse:backports_sle:15.0:sp2:*:*:*:*:*:*
- cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
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