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NVD / CVE Program· CNA mitre

CVE-2021-39272: Fetchmail before 6.4.22 fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and…

MediumCVSS 5.9 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 23/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.92% (FIRST EPSS); higher than 60.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: fetchmail (AlmaLinux:8) 6.4.24-1.el8; fetchmail (Alpine:v3.14) 6.4.22-r0; fetchmail (Debian:12) 6.4.22-1.

Low priority for now. Upgrade to fetchmail (AlmaLinux:8) 6.4.24-1.el8; fetchmail (Alpine:v3.14) 6.4.22-r0; fetchmail (Debian:12) 6.4.22-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Fetchmail before 6.4.22 fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and PREAUTH.

Published
Aug 30, 2021
Updated
Jun 17, 2026
EPSS
0.9% · 60th percentile

Report tools

JSON

Action score

23

Monitor

Low priority for now.

CVSS
23 / 40 · 5.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
fetchmailfetchmail
fedoraprojectfedora

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Affected versions

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

  • fedoraproject fedora33
  • fedoraproject fedora34
  • fedoraproject fedora35
  • fetchmail fetchmailbefore 6.4.22

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8fetchmailbefore 6.4.24-1.el86.4.24-1.el8
Alpine:v3.14fetchmailbefore 6.4.22-r06.4.22-r0
Debian:12fetchmailbefore 6.4.22-16.4.22-1
openSUSE:Leap 15.2fetchmailbefore 6.3.26-lp152.6.9.16.3.26-lp152.6.9.1
openSUSE:Leap 15.2fetchmailbefore 6.4.22-lp152.6.12.16.4.22-lp152.6.12.1
openSUSE:Leap 15.3fetchmailbefore 6.4.22-20.20.16.4.22-20.20.1
openSUSE:Leap 15.3fetchmailbefore 6.3.26-20.17.16.3.26-20.17.1
openSUSE:Tumbleweedfetchmailbefore 6.4.22-1.16.4.22-1.1
Red Hat:enterprise_linux:8::appstreamfetchmailbefore 0:6.4.24-1.el80:6.4.24-1.el8
Red Hat:enterprise_linux:8::appstreamfetchmail-debuginfobefore 0:6.4.24-1.el80:6.4.24-1.el8
Red Hat:enterprise_linux:8::appstreamfetchmail-debugsourcebefore 0:6.4.24-1.el80:6.4.24-1.el8
Rocky Linux:8fetchmailbefore 0:6.4.24-1.el80:6.4.24-1.el8
SUSE:Linux Enterprise Module for Basesystem 15 SP2fetchmailbefore 6.3.26-20.17.16.3.26-20.17.1
SUSE:Linux Enterprise Module for Basesystem 15 SP2fetchmailbefore 6.4.22-20.20.16.4.22-20.20.1
SUSE:Linux Enterprise Server 12 SP5fetchmailbefore 6.3.26-13.15.16.3.26-13.15.1

Same product

fetchmail: all records

Other highest-scoring records for the same primary product.

  • CVE-2001-1009Fetchmail (aka fetchmail-ssl) before 5.8.17 allows a remote malicious (1) IMAP server or (2) POP/POP3 server to overwrite arbitrary memory…
    42Plan
  • CVE-2001-0101Vulnerability in fetchmail 5.5.0-2 and earlier in the AUTHENTICATE GSSAPI command.
    41Plan
  • CVE-2006-5974fetchmail 6.3.5 and 6.3.6 before 6.3.6-rc4, when refusing a message delivered via the mda option, allows remote attackers to cause a denial…
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2012-3482Dec 21, 2012 · Fetchmail 5.0.8 through 6.3.21, when using NTLM authentication in debug mode, allows remote NTLM servers to (1) cause a denial of service…
    24Monitor
  • ← EarlierCVE-2021-36386Jul 30, 2021 · report_vbuild in report.c in Fetchmail before 6.4.20 sometimes omits initialization of the vsnprintf va_list argument, which might allow…
    31Monitor
  • Later →CVE-2025-61962Oct 4, 2025 · In fetchmail before 6.5.6, the SMTP client can crash when authenticating upon receiving a 334 status code in a malformed context.
    23Monitor

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
almalinux:fetchmail6.4.24-1.el8 · AlmaLinux:8Package registry (OSV)
alpine:fetchmail6.4.22-r0 · Alpine:v3.14Package registry (OSV)
debian:fetchmail6.4.22-1 · Debian:12Package registry (OSV)
opensuse:fetchmail6.3.26-lp152.6.9.1 · openSUSE:Leap 15.2Package registry (OSV)
red hat:fetchmail0:6.4.24-1.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:fetchmail-debuginfo0:6.4.24-1.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:fetchmail-debugsource0:6.4.24-1.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
rocky linux:fetchmail0:6.4.24-1.el8 · Rocky Linux:8Package registry (OSV)
suse:fetchmail6.3.26-13.15.1 · SUSE:Linux Enterprise Server 12 SP5Package 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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-319 · Cleartext Transmission of Sensitive Information

CVSS vector

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

References

Show all references (6 more)

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

All records