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CVE Record

CVE-2021-33515: The submission service in Dovecot before 2.3.15 allows STARTTLS command injection in lib-smtp.

The submission service in Dovecot before 2.3.15 allows STARTTLS command injection in lib-smtp. Sensitive information can be redirected to an attacker-controlled address.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This issue affects Dovecot mail submission service versions before 2.3.15. A STARTTLS command injection flaw in lib-smtp can let sensitive information be redirected to an attacker-controlled address. For executives, the concern is mail confidentiality and potential message misdirection on exposed or business-critical mail infrastructure.

Executive priority

Treat this as a prioritized mail-platform maintenance issue, especially for externally reachable Dovecot submission servers. It is not KEV-listed in the provided bundle, but the stated impact involves sensitive information redirection, which can create business and confidentiality exposure.

Technical view

CVE-2021-33515 is a STARTTLS command injection vulnerability in Dovecot's submission service via lib-smtp before 2.3.15. The provided sources state sensitive information can be redirected to an attacker-controlled address. The bundle does not provide CVSS, CWE, exploit details, or affected CPEs.

Likely exposure

Organizations running Dovecot submission service before 2.3.15 are the likely exposure group. Exposure is higher where submission is internet-accessible or relays sensitive business mail. Fedora, Gentoo, and Debian LTS advisories indicate downstream package updates existed, but local package versions must be checked.

Exploitation context

The source bundle does not show CISA KEV listing or cite active exploitation. The available evidence supports a command injection risk with sensitive information redirection, but does not establish exploitation in the wild, exploit maturity, or attacker prerequisites.

Researcher notes

Evidence is limited to the CVE description and vendor/distribution advisories. Do not assume specific CPEs, exploit availability, or active campaigns from this bundle. Research should focus on confirming Dovecot version, submission service enablement, package backports, and vendor advisory details.

Mitigation direction

  • Upgrade Dovecot to 2.3.15 or later where applicable.
  • Apply the relevant Fedora, Gentoo, Debian, or vendor security package update.
  • Check Dovecot security guidance for supported fixed versions.
  • Limit mail submission exposure to required networks where operationally possible.
  • Review mail routing and submission logs for unexpected redirection indicators.

Validation and detection

  • Inventory hosts running Dovecot submission service.
  • Confirm installed Dovecot versions are not earlier than 2.3.15.
  • Verify distro security updates are applied on managed packages.
  • Check whether submission service is enabled and externally reachable.
  • Review mail flow logs for unusual recipient or relay behavior.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2021-33515 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.