Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.47% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-29157High confidence
Dovecot before 2.3.15 allows ../ Path Traversal
Unknown · Unknown
7.5HighCVSS 3.1
Within 7 days
Fix not verifiedHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Medium, lowered one band.downgradedsince 3 Aug 2024
Compensating controls
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
7 package statesRelease-specific package status
Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Alpine v3.23v3.23 · main | dovecot | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.3.15-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.22v3.22 · main | dovecot | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.3.15-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.21v3.21 · main | dovecot | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.3.15-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Debian trixietrixie · source | dovecot | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3.13+dfsg1-2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | dovecot | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3.13+dfsg1-2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | dovecot | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3.13+dfsg1-2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | dovecot | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.3.13+dfsg1-2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
Dovecot before 2.3.15 allows ../ Path Traversal. An attacker with access to the local filesystem can trick OAuth2 authentication into using an HS256 validation key from an attacker-controlled location. This occurs during use of local JWT validation with the posix fs driver.
What
Dovecot before 2.3.15 allows ../ Path Traversal. An attacker with access to the local filesystem can trick OAuth2 authentication into using an HS256 validation key from an attacker-controlled location. This occurs during use of local JWT validation with the posix fs driver.
Why
Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Dovecot before 2.3.15 allows ../ Path Traversal. An attacker with access to the local filesystem can trick OAuth2 authentication into using an HS256 validation key from an attacker-controlled location. This occurs during use of local JWT validation with the posix fs driver.
Why
Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-22 ↗
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AC:H/AV:L/A:N/C:H/I:H/PR:L/S:C/UI:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.AVLocalAttack vector: The attacker needs local access to the vulnerable system.ANoneAvailability impact: No direct loss is represented by this metric.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.PRLowPrivileges required: The attacker needs basic user-level privileges.SChangedScope: The attack can affect a component governed by a different security authority.UINoneUser interaction: No action by another user is required.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- n/a
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 28 Jun 2021 · Last source change 3 Aug 2024, 22:02 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-15796
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.