In Dovecot before 2.3.11.3, sending a specially formatted NTLM request will crash the auth service because of an out-of-bounds read.
- Published
- Aug 12, 2020
- Updated
- Jun 16, 2026
- EPSS
- 6.2% · 93th percentile
- CWE
- CWE-125
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 6.2%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| dovecot | dovecot | cpe:2.3:a:dovecot:dovecot |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
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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.
- dovecot dovecotbefore 2.3.11.3
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | dovecot | before 2.3.10.1-r1 | 2.3.10.1-r1 |
| Alpine:v3.12 | dovecot | before 2.3.11.3-r0 | 2.3.11.3-r0 |
| Debian:10 | dovecot | before 1:2.3.4.1-5+deb10u3 | 1:2.3.4.1-5+deb10u3 |
| Debian:12 | dovecot | before 1:2.3.11.3+dfsg1-1 | 1:2.3.11.3+dfsg1-1 |
| Debian:9 | dovecot | before 1:2.2.27-3+deb9u6 | 1:2.2.27-3+deb9u6 |
| openSUSE:Leap 15.1 | dovecot23 | before 2.3.10-lp151.2.12.1 | 2.3.10-lp151.2.12.1 |
| openSUSE:Leap 15.2 | dovecot23 | before 2.3.10-lp152.2.3.1 | 2.3.10-lp152.2.3.1 |
| openSUSE:Tumbleweed | dovecot23 | before 2.3.16-1.6 | 2.3.16-1.6 |
| openSUSE:Tumbleweed | dovecot24 | before 2.4.0-1.1 | 2.4.0-1.1 |
| Red Hat:enterprise_linux:7::server | dovecot | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:7::server | dovecot-debuginfo | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:7::server | dovecot-devel | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:7::server | dovecot-mysql | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:7::server | dovecot-pgsql | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:7::server | dovecot-pigeonhole | before 1:2.2.36-6.el7_8.1 | 1:2.2.36-6.el7_8.1 |
| Red Hat:enterprise_linux:8::appstream | dovecot | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-debuginfo | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-debugsource | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-mysql | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-mysql-debuginfo | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-pgsql | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-pgsql-debuginfo | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-pigeonhole | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
| Red Hat:enterprise_linux:8::appstream | dovecot-pigeonhole-debuginfo | before 1:2.3.8-2.el8_2.2 | 1:2.3.8-2.el8_2.2 |
+23
Same product
dovecot: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-11500In Dovecot before 2.2.36.4 and 2.3.x before 2.3.7.2 (and Pigeonhole before 0.5.7.2), protocol processing can fail for quoted strings.58Plan
- CVE-2020-7046lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated45Plan
- CVE-2016-8652The auth component in Dovecot before 2.2.27, when auth-policy is configured, allows a remote attackers to cause a denial of service (crash) 37Monitor
- CVE-2026-27851When safe filter is used with variable expansion, all following pipelines on the same string are incorrectly interpreted as safe too, enabli36Monitor
- CVE-2022-30550An issue was discovered in the auth component in Dovecot 2.2 and 2.3 before 2.3.20.36Monitor
- CVE-2017-14461A specially crafted email delivered over SMTP and passed on to Dovecot by MTA can trigger an out of bounds read resulting in potential sensi33Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:dovecot | 2.3.10.1-r1 · Alpine:v3.10 | Package registry (OSV) |
| debian:dovecot | 1:2.3.11.3+dfsg1-1 · Debian:12 | Package registry (OSV) |
| opensuse:dovecot23 | 2.3.10-lp151.2.12.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:dovecot24 | 2.4.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:dovecot | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-debuginfo | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-debugsource | 1:2.3.8-2.el8_2.2 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:dovecot-devel | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-mysql | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-mysql-debuginfo | 1:2.3.8-2.el8_2.2 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:dovecot-pgsql | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-pgsql-debuginfo | 1:2.3.8-2.el8_2.2 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:dovecot-pigeonhole | 1:2.2.36-6.el7_8.1 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:dovecot-pigeonhole-debuginfo | 1:2.3.8-2.el8_2.2 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| suse:dovecot22 | 2.2.31-19.22.1 · SUSE:HPE Helion OpenStack 8 | Package registry (OSV) |
| suse:dovecot23 | 2.3.10-4.27.1 · SUSE:Linux Enterprise High Performance Computing 15-ESPOS | Package 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
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.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2020-08/msg00048.html
- lists.opensuse.org/opensuse-security-announce/2020-08/msg00059.html
- dovecot.org/security
- lists.debian.org/debian-lts-announce/2020/08/msg00024.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4AAX2MJEULPVSRZOBX3PNPFSYP4FM4TT/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EYZU6CHA3VMYYAUCMHSCCQKJEVEIKPQ2/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XKKAL3OMG76ZZ7CIEMQP2K6KCTD2RAKE/
- security.gentoo.org/glsa/202009-02
- usn.ubuntu.com/4456-1/
- usn.ubuntu.com/4456-2/
- www.debian.org/security/2020/dsa-4745
Vendor advisories and official records. Exploit/PoC links are deliberately left out.