Security readout for executives and security teams
Plain-English summary
CVE-2018-6918 is a remote denial-of-service flaw in FreeBSD IPsec packet handling. A malformed packet can trigger an infinite loop and crash the machine. The business impact is availability loss for exposed FreeBSD systems or products using the affected code.
Executive priority
Prioritize patching exposed infrastructure where downtime is costly. This is not documented as exploited in the bundle, but a remote crash condition can create operational disruption and should not remain on internet-reachable systems.
Technical view
The IPsec option header length field does not count the option header itself. When the length is zero, parsing may stop advancing and loop indefinitely. FreeBSD fixed this before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8, and 10.3-RELEASE-p28.
Likely exposure
Likely exposure is FreeBSD systems older than the fixed releases. Risk depends on whether arbitrary packets can reach the affected IPsec parsing path. Apple advisory references are present, but the bundle does not provide enough detail to define exact Apple exposure here.
Exploitation context
The source bundle says a remote attacker able to send an arbitrary packet may crash the machine. It does not cite active exploitation, public weaponization, or KEV listing. Treat this as a remotely triggerable availability issue, not proven active exploitation.
Researcher notes
Focus analysis on IPsec option parsing and zero-length header behavior. The provided sources do not include CVSS, CWE, exploit status, or detailed Apple product scope, so avoid expanding affected-product claims beyond cited advisories.
Mitigation direction
- Upgrade FreeBSD to the fixed STABLE or RELEASE patch level named by FreeBSD.
- Review FreeBSD-SA-18:05 for vendor-specific upgrade and workaround guidance.
- Check Apple advisory pages for any referenced affected AirPort firmware guidance.
- Limit untrusted network paths to systems until vendor updates are applied.
Validation and detection
- Inventory FreeBSD versions and compare them with the fixed release levels.
- Confirm whether affected hosts process IPsec traffic from untrusted networks.
- Review crash or availability logs for unexplained packet-triggered failures.
- Verify vendor advisory applicability for any FreeBSD-derived appliances.
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.
CVE-2018-6918 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- FreeBSD-SA-18:05CVE reference · vendor-advisory, x_refsource_FREEBSD
- https://support.apple.com/kb/HT210090CVE reference · x_refsource_CONFIRM
- 20190531 APPLE-SA-2019-5-30-1 AirPort Base Station Firmware Update 7.9.1CVE reference · mailing-list, x_refsource_BUGTRAQ
- https://support.apple.com/kb/HT210091CVE reference · x_refsource_CONFIRM
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.