Security readout for executives and security teams
Plain-English summary
OpenSSH before 7.6 had a flaw where SFTP readonly mode could still allow creation of empty files. This is an integrity issue, not a data theft or system takeover issue based on the provided sources. Business risk is highest where readonly SFTP access is used to protect shared directories, regulated file drops, or operational workflows.
Executive priority
Treat as a moderate maintenance priority. It is not described as actively exploited and impact is limited, but it weakens a security boundary many teams may trust for file integrity. Prioritize faster where readonly SFTP protects customer, partner, or operational file exchange locations.
Technical view
CVE-2017-15906 affects OpenSSH sftp-server.c process_open before 7.6. Readonly mode did not fully block write behavior, allowing creation of zero-length files. The CVSS 3.1 score is 5.3 with low integrity impact. CWE-732 indicates incorrect permission assignment or enforcement. Multiple vendor advisories reference downstream fixes.
Likely exposure
Systems running OpenSSH before 7.6 with sftp-server readonly mode are the clearest exposure. Downstream exposure may exist in Linux distributions, appliances, and products covered by the listed Gentoo, Red Hat, Debian, NetApp, Oracle, and Siemens advisories.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The described impact is limited to creating zero-length files despite readonly mode. No evidence in the bundle supports confidentiality loss, privilege escalation, or arbitrary file writes.
Researcher notes
The affected field in the bundle is generic, so product scoping should come from OpenSSH versioning and vendor advisories. The OpenBSD commit and OpenSSH 7.6 release are primary technical anchors. Avoid expanding impact beyond zero-length file creation unless newer vendor evidence supports it.
Mitigation direction
- Upgrade OpenSSH to 7.6 or a vendor-supported fixed package.
- Apply relevant Gentoo, Red Hat, Debian, NetApp, Oracle, or Siemens guidance where applicable.
- Identify services depending on sftp-server readonly mode for integrity control.
- Limit SFTP access to trusted users and networks where operationally possible.
- Do not rely on readonly mode alone until fixed packages are confirmed.
Validation and detection
- Inventory OpenSSH versions and flag releases before 7.6.
- Review SFTP configurations for readonly-mode use.
- Confirm vendor security updates are installed on affected platforms.
- Check managed directories for unexpected zero-length files.
- Verify vulnerability scanners map findings to CVE-2017-15906.
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-732: 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-2017-15906 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
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A: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
1 official scoreWe 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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N3.91.4CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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
- https://www.openssh.com/txt/release-7.6CVE reference, mitre
- https://github.com/openbsd/src/commit/a6981567e8e215acc1ef690c8dbb30f2d9b00a19CVE reference, mitre
- GLSA-201801-05CVE reference, mitre · vendor-advisory
- https://security.netapp.com/advisory/ntap-20180423-0004/CVE reference, mitre
- RHSA-2018:0980CVE reference, mitre · vendor-advisory
- [debian-lts-announce] 20180910 [SECURITY] [DLA 1500-1] openssh security updateCVE reference, mitre · mailing-list
- https://www.oracle.com/security-alerts/cpujan2020.htmlCVE reference, mitre
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdfCVE reference, mitre
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.
Incorrect Permission Assignment for Critical Resource
Incorrect Permission Assignment for Critical Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.