CVE-2020-12673: 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.
Noroxi assessment
Priority: Monitor (action score 32/100)
- 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: 6.1% (FIRST EPSS); higher than 93.5% 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. No special conditions are required; it is repeatable.
- Fixed version: dovecot (Alpine:v3.10) 2.3.10.1-r1; dovecot (Alpine:v3.12) 2.3.11.3-r0; dovecot (Debian:10) 1:2.3.4.1-5+deb10u3.
- Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to dovecot (Alpine:v3.10) 2.3.10.1-r1; dovecot (Alpine:v3.12) 2.3.11.3-r0; dovecot (Debian:10) 1:2.3.4.1-5+deb10u3 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
- Published
- Aug 12, 2020
- Updated
- Jun 16, 2026
- EPSS
- 6.1% · 93th percentile
- CWE
- CWE-125
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 · 6.1%
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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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.
We use this product, ask for helpAffected 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.
| 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 |
Using dovecot? Add it to your stack and be the first to know about CVEs like this one. (Email server)
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
Published before and after this one in the same product
- ← EarlierCVE-2020-10967May 18, 2020 · In Dovecot before 2.3.10.1, remote unauthenticated attackers can crash the lmtp or submission process by sending mail with an empty localpar23Monitor
- ← EarlierCVE-2020-12100Aug 12, 2020 · In Dovecot before 2.3.11.3, uncontrolled recursion in submission, lmtp, and lda allows remote attackers to cause a denial of service (resour32Monitor
- Later →CVE-2020-12674Aug 12, 2020 · In Dovecot before 2.3.11.3, sending a specially formatted RPA request will crash the auth service because a length of zero is mishandled.32Monitor
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.
No history yet (it accumulates with the daily EPSS job).
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-20-684 · Sep 8, 2020(Dovecot Sunucu Güvenlik Güncellemesi)
- TR-20-652 · Aug 27, 2020(Dovecot Sunucu Güvenlik Güncellemesi)
- TR-20-615 · Aug 17, 2020(Dovecot Sunucu Güvenlik Güncellemesi)
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
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (10 more)Show less
- 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.