CVE-2018-20764

CVE-2018-20764 is a critical-severity vulnerability in Helpsystems Boks with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.

Frequently asked questions

What is CVE-2018-20764?
A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.
How severe is CVE-2018-20764?
CVE-2018-20764 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-20764 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20764?
CVE-2018-20764 affects Helpsystems Boks. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20764?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-20764 published?
CVE-2018-20764 was published on 2019-02-08 and last updated on 2026-06-17.

References

Affected products (1)