CVE-2021-38373

FAUCET Score

CVE-2021-38373 describes a vulnerability in KDE KMail versions up to 19.12.3 (aka 5.13.3) where the SMTP STARTTLS option is not enforced, leading to cleartext transmission of emails unless server authentication is explicitly enabled. This medium-severity vulnerability (CVSS 5.3) has a high confidentiality impact, allowing an attacker to intercept sensitive information due to the lack of encryption. There is currently no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		19.12.3CPE matchmatch criteria	cpe:2.3:a:kde:kmail:19.12.3:::::::*

CVSS Data

CVSS version used by this source: 3.1

5.3MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

Exploitability Score

1.6

Impact Score

3.6

CvssVersion

3.1

Exploit Intelligence

EPSS Score

0.53%

Probability of exploitation in next 30 days

EPSS Percentile

41.6%

Percentile rank of EPSS score among Peer Group

As of 2026-07-28

Model: v2026.06.15

This CVE's current EPSS score of 0.0053 is in the 32nd percentile among its peer group of 1,428 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Advisories (1)

redhatCVE-2021-38373Moderate

kmail: STARTTLS is ignored when "Server requires authentication" not checked in UI

Aug 9, 2021

References

bugs.kde.org / show_bug.cgi

Mailing ListVendor Advisory

nostarttls.secvuln.info

Third Party Advisory