Security readout for executives and security teams
Plain-English summary
CVE-2018-20764 is a buffer overflow in HelpSystems tcpcrypt on Linux, used with BoKS encrypted telnet through BoKS 6.7.1. Because tcpcrypt runs setuid, successful exploitation can raise an attacker's privileges on an affected host.
Executive priority
Prioritize remediation where BoKS encrypted telnet remains in use, especially on administrative or production Linux hosts. The issue enables privilege escalation, but current evidence does not show confirmed active exploitation.
Technical view
The CVE record describes a buffer overflow in the Linux tcpcrypt component for BoKS encrypted telnet through version 6.7.1. The key security impact is privilege escalation because the binary is setuid. The provided sources do not include CVSS, CWE mapping, exploit details, or full remediation instructions.
Likely exposure
Exposure appears limited to Linux systems using HelpSystems/Fox Technologies BoKS encrypted telnet with tcpcrypt through BoKS 6.7.1.
Exploitation context
CISA KEV is false, and the provided sources do not cite active exploitation. Exploitability depends on access to the affected tcpcrypt context.
Researcher notes
The public source bundle is sparse: no CVSS vector, CWE, exploit status, or detailed fix text is included. Analysis should stay anchored to the CVE description and the referenced HelpSystems hotfix page.
Mitigation direction
- Inventory BoKS encrypted telnet deployments on Linux.
- Confirm whether tcpcrypt is present and setuid on those systems.
- Review the HelpSystems/Fox Technologies hotfix guidance.
- Apply the applicable vendor hotfix or supported upgrade path.
- Restrict access to affected hosts until remediation is complete.
Validation and detection
- Check installed BoKS versions against the affected through-6.7.1 range.
- Verify whether Linux hosts include the tcpcrypt component.
- Confirm vendor hotfix or upgrade status in asset records.
- Review privileged binary permissions for tcpcrypt on affected hosts.
- Monitor for suspicious privilege escalation activity on impacted systems.
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.
Privilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-20764 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
- https://community.helpsystems.com/knowledge-base/fox-technologies/hotfix/515/CVE 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.