CVE-2021-38370

In Alpine through 2.24, untagged responses from an IMAP server are accepted before STARTTLS.

5.9 MediumFix available

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: High
Availability: None

Exploit likelihood

1.56%Up 0.9 points since Aug 11, 2021

What each source reports

NVD Score used 5.9

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: CVE-2021-38370
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness: CWE-77
Updated: 2026-11-02

CVE List No score

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: CVE-2021-38370
Updated: 2026-11-02

EUVDEUVD-2021-24823 No score

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: EUVD-2021-24823
Updated: 2026-11-03

GitHub AdvisoriesGHSA-2c2h-qvww-cw95 5.9

In Alpine through 2.24, untagged responses from an IMAP server are accepted before STARTTLS.

In Alpine through 2.24, untagged responses from an IMAP server are accepted before STARTTLS.

Record: GHSA-2c2h-qvww-cw95
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness: CWE-77
Updated: 2026-11-02

OSVALPINE-CVE-2021-38370 5.9

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: ALPINE-CVE-2021-38370
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-03

OSV 5.9

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: CVE-2021-38370
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-02

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OSVDEBIAN-CVE-2021-38370 5.9

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: DEBIAN-CVE-2021-38370
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-38370 5.9

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Record: UBUNTU-CVE-2021-38370
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated: 2026-11-02

OSVopenSUSE-SU-2024:12314-1 No score

alpine-2.26-27.1 on GA media

These are all security issues fixed in the alpine-2.26-27.1 package on the GA media of openSUSE Tumbleweed.

Record: openSUSE-SU-2024:12314-1
Updated: 2026-11-02

OSVUSN-7360-1 No score

alpine vulnerabilities

It was discovered that Alpine did not use a secure connection under certain circumstances. A remote attacker could possibly use this issue to leak sensitive information. (CVE-2020-14929)

It was discovered that Alpine could allow untagged responses from an IMAP server before upgrading to a TLS connection. A remote attacker could possibly use this issue to leak sensitive information. (CVE-2021-38370)

It was discovered that Alpine could crash when receiving certain SMTP commands. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2021-46853)

Record: USN-7360-1
Updated: 2026-11-02

Affected products

alpine project alpine

Affected packages

Affected packages
Package	Affected	Fixed
`alpine` Alpine:v3.15	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.16	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.17	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.18	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.19	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.20	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.21	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.22	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.23	before 2.25-r0	2.25-r0
`alpine` Alpine:v3.24	before 2.25-r0	2.25-r0

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Affected packages
Package	Affected	Fixed
`alpine` Debian:12	before 2.25+dfsg1-1	2.25+dfsg1-1
`alpine` Debian:13	before 2.25+dfsg1-1	2.25+dfsg1-1
`alpine` Debian:14	before 2.25+dfsg1-1	2.25+dfsg1-1
`alpine` Ubuntu:Pro:16.04:LTS	before 2.20+dfsg1-2ubuntu0.1~esm1, plus listed versions 2.20+dfsg1-12.20+dfsg1-2	2.20+dfsg1-2ubuntu0.1~esm1
`alpine` Ubuntu:Pro:18.04:LTS	before 2.21+dfsg1-1ubuntu0.1~esm1, plus listed versions 2.20+dfsg1-72.21+dfsg1-12.21+dfsg1-1build1	2.21+dfsg1-1ubuntu0.1~esm1
`alpine` Ubuntu:Pro:20.04:LTS	before 2.22+dfsg1-1ubuntu0.1~esm1, plus listed versions 2.21+dfsg1-1.1build12.22+dfsg1-1	2.22+dfsg1-1ubuntu0.1~esm1
`alpine` Ubuntu:Pro:16.04:LTS From an advisory covering 3 CVEs	before 2.20+dfsg1-2ubuntu0.1~esm1, plus listed versions 2.20+dfsg1-12.20+dfsg1-2	2.20+dfsg1-2ubuntu0.1~esm1
`alpine` Ubuntu:Pro:18.04:LTS From an advisory covering 3 CVEs	before 2.21+dfsg1-1ubuntu0.1~esm1, plus listed versions 2.20+dfsg1-72.21+dfsg1-12.21+dfsg1-1build1	2.21+dfsg1-1ubuntu0.1~esm1
`alpine` Ubuntu:Pro:20.04:LTS From an advisory covering 3 CVEs	before 2.22+dfsg1-1ubuntu0.1~esm1, plus listed versions 2.21+dfsg1-1.1build12.22+dfsg1-1	2.22+dfsg1-1ubuntu0.1~esm1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	affected, aliases, references	OSV
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-38370 is a medium vulnerability (CVSS 5.9) in Alpine Project Alpine, published August 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.56%, the 75th percentile. Fixed in alpine 2.25-r0.

References

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