Security readout for executives and security teams
Plain-English summary
Rsync daemons using hostname-based deny rules may fail open when DNS resolution breaks. An unauthenticated remote attacker able to induce that failure could bypass module access restrictions and reach restricted file trees, potentially exposing or altering sensitive files. The issue affects rsync 3.1.0 through versions before 3.5.0.
Executive priority
Treat as an urgent remediation item where affected daemons are remotely reachable and hostname-based deny rules protect valuable data. Upgrade those systems first. Lower priority only after confirming the daemon is outside the affected range or does not use the implicated access-control pattern.
Technical view
During module authorization, affected rsync daemons skip a hostname-based hosts deny rule when its DNS lookup fails instead of denying access. This creates an authorization bypass across a network boundary. Exploitation requires the attacker to induce DNS failure, reflected by high attack complexity, but requires no privileges or user interaction.
Likely exposure
Exposure requires an affected rsync daemon, a version from 3.1.0 through before 3.5.0, and module restrictions relying on hostname-based deny rules. Internet-facing or broadly reachable daemons protecting sensitive or writable module file trees warrant the fastest review. Other configurations are not established as affected by the supplied sources.
Exploitation context
The bundle marks this CVE as absent from KEV and provides no cited evidence of active exploitation. Exploitation is nevertheless remotely reachable and unauthenticated, but depends on inducing DNS resolution failure during access-control evaluation. The supplied CVSS 4.0 score is 9.1 with high attack complexity and high confidentiality and integrity impact.
Researcher notes
CWE-636 and CWE-863 align with fail-open authorization and incorrect access-control enforcement. The key validation boundary is DNS lookup failure while evaluating hostname-based deny rules. The supplied evidence identifies confidentiality and integrity impact, not availability impact. No affected products beyond RsyncProject rsync are established.
Mitigation direction
- Upgrade affected rsync installations to version 3.5.0 or later.
- Prioritize reachable daemons exposing sensitive or writable module file trees.
- Check the vendor advisory before applying any temporary configuration workaround.
- Restrict network access to affected daemons until upgrades are completed.
Validation and detection
- Inventory rsync daemon versions and identify installations below 3.5.0 but at least 3.1.0.
- Inspect module configurations for hostname-based hosts deny rules.
- Confirm which affected daemons are reachable from untrusted networks.
- Test authorization behavior during controlled DNS failure in an isolated environment.
- Review access records for unexpected connections to restricted modules.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-636: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-863: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-70452 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
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.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N2.25.2VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.1CriticalVector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- GitHub Security Advisory (GHSA-6692-28cx-wpqq)CVE reference, VulnCheck · vendor-advisory
- rsync 3.5.0 Release NotesCVE reference, VulnCheck · release-notes
- https://www.vulncheck.com/advisories/rsync-access-control-bypass-via-dns-resolution-failureCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Not Failing Securely ('Failing Open')
Not Failing Securely ('Failing Open') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Incorrect Authorization
Incorrect Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.