dovecot: Dovecot DoS when passdb dict was used for authentication
Published Jun 21, 2018
7.5
HIGHCVSS 3.0
EPSS 4.46%
Description
Dovecot before version 2.2.29 is vulnerable to a denial of service. When 'dict' passdb and userdb were used for user authentication, the username sent by the IMAP/POP3 client was sent through var_expand() to perform %variable expansion. Sending specially crafted %variable fields could result in excessive memory usage causing the process to crash (and restart), or excessive CPU usage causing all authentications to hang.
Affected products
- Vendor n/a Product Dovecot Defaultn/a
- Version dovecot 2.2.29StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Dovecot | n/a |
|
Configuration 2
- 8.0
No data.
Red Hat Enterprise Linux 5
dovecot
Not affected
Red Hat Enterprise Linux 6
dovecot
Not affected
Red Hat Enterprise Linux 7
dovecot
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | dovecot | Not affected | n/a |
| Red Hat Enterprise Linux 6 | dovecot | Not affected | n/a |
| Red Hat Enterprise Linux 7 | dovecot | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Versions of dovecot shipped in Red Hat Enterprise Linux 5, 6 and 7 are not affected by this vulnerability.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
AV:N/AC:L/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (20 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 4.46% (0.04465) | 91.14th | v5 (v2026.06.15) |
| Jun 15, 2026 | 4.64% (0.04640) | 90.51th | v5 (v2026.06.15) |
| Mar 17, 2025 | 7.52% (0.07518) | 91.17th | v4 (v2025.03.14) |
| Dec 17, 2024 | 3.19% (0.03194) | 90.96th | v3 (v2023.03.01) |
| Jan 15, 2024 | 1.33% (0.01330) | 84.56th | v3 (v2023.03.01) |
| Dec 22, 2023 | 1.88% (0.01875) | 87.11th | v3 (v2023.03.01) |
| Nov 12, 2023 | 1.62% (0.01620) | 86.03th | v3 (v2023.03.01) |
| Jul 20, 2023 | 3.10% (0.03099) | 89.72th | v3 (v2023.03.01) |
| Jul 8, 2023 | 4.33% (0.04326) | 91.14th | v3 (v2023.03.01) |
| Jun 15, 2023 | 2.60% (0.02596) | 88.78th | v3 (v2023.03.01) |
| May 8, 2023 | 3.17% (0.03166) | 89.68th | v3 (v2023.03.01) |
| Mar 7, 2023 | 5.25% (0.05250) | 91.80th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.11% (0.01108) | 55.18th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.11% (0.01108) | 53.57th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.11% (0.01108) | 51.54th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.11% (0.01108) | 29.61th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.81% (0.01806) | 35.10th | v1 |
| Jan 6, 2022 | 1.81% (0.01806) | 34.40th | v1 |
| Sep 1, 2021 | 1.81% (0.01806) | 74.37th | v1 |
| Apr 14, 2021 | 1.81% (0.01806) | 0.00th | v1 |
References (10)
- http://www.openwall.com/lists/oss-security/2017/04/11/1 mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- http://www.securityfocus.com/bid/97536 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2017-2669 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1438676 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2669 x_refsource_CONFIRMIssue TrackingThird Party Advisory
- https://dovecot.org/pipermail/dovecot-news/2017-April/000341.html mailing-listx_refsource_MLISTVendor Advisory
- https://github.com/dovecot/core/commit/000030feb7a30f193197f1aab8a7b04a26b42735.patch x_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2017-2669
- https://www.cve.org/CVERecord?id=CVE-2017-2669
- https://www.debian.org/security/2017/dsa-3828 vendor-advisoryx_refsource_DEBIANThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.openwall.com/lists/oss-security/2017/04/11/1 | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| http://www.securityfocus.com/bid/97536 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| https://access.redhat.com/security/cve/CVE-2017-2669 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1438676 | Issue Tracking | |
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2669 | x_refsource_CONFIRMIssue TrackingThird Party Advisory | |
| https://dovecot.org/pipermail/dovecot-news/2017-April/000341.html | mailing-listx_refsource_MLISTVendor Advisory | |
| https://github.com/dovecot/core/commit/000030feb7a30f193197f1aab8a7b04a26b42735.patch | x_refsource_CONFIRMThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2017-2669 | ||
| https://www.cve.org/CVERecord?id=CVE-2017-2669 | ||
| https://www.debian.org/security/2017/dsa-3828 | vendor-advisoryx_refsource_DEBIANThird Party Advisory |
Change history (0)
No recorded changes yet.