Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2022-2928 — isc / dhcp

NULL Pointer Dereference

In ISC DHCP 4.4.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1, when the function option_code_hash_lookup() is called from add_option(), it increases the option's refcount field. However, there is not a corresponding call to option_dereference() to decrement the refcount field. The function add_option() is only used in server responses to lease query packets. Each lease query response calls this function for several options, so eventually, the reference counters could overflow and cause the server to abort.

  • Published: Oct 7, 2022
  • Updated: Sep 13, 2026
  • CVE: CVE-2022-2928
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWEs:

Software Affected versions
isc / dhcp >= 4.4.0, <= 4.4.3
isc / dhcp = 4.1-esv-r1
isc / dhcp = 4.1-esv-r10
isc / dhcp = 4.1-esv-r10_b1
isc / dhcp = 4.1-esv-r10_rc1
isc / dhcp = 4.1-esv-r10b1
isc / dhcp = 4.1-esv-r10rc1
isc / dhcp = 4.1-esv-r11
isc / dhcp = 4.1-esv-r11_b1
isc / dhcp = 4.1-esv-r11_rc1
isc / dhcp = 4.1-esv-r11_rc2
isc / dhcp = 4.1-esv-r11b1
isc / dhcp = 4.1-esv-r11rc1
isc / dhcp = 4.1-esv-r11rc2
isc / dhcp = 4.1-esv-r12
isc / dhcp = 4.1-esv-r12-p1
isc / dhcp = 4.1-esv-r12_b1
isc / dhcp = 4.1-esv-r12_p1
isc / dhcp = 4.1-esv-r12b1
isc / dhcp = 4.1-esv-r13
isc / dhcp = 4.1-esv-r13_b1
isc / dhcp = 4.1-esv-r13b1
isc / dhcp = 4.1-esv-r14
isc / dhcp = 4.1-esv-r14_b1
isc / dhcp = 4.1-esv-r14b1
isc / dhcp = 4.1-esv-r15
isc / dhcp = 4.1-esv-r15-p1
isc / dhcp = 4.1-esv-r15_b1
isc / dhcp = 4.1-esv-r16
isc / dhcp = 4.1-esv-r16-p1
debian / debian_linux = 10.0
fedoraproject / fedora = 35
fedoraproject / fedora = 36
fedoraproject / fedora = 37

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.