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Hostapd CVE-2019-11555

MEDIUM
NULL Pointer Dereference (CWE-476)
2019-04-26 cve@mitre.org
5.9
CVSS 3.0 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 5.9 (MEDIUM). Attack characteristics: network attack vector, high complexity, no privileges required, no user interaction not required.

Exploit ScenarioDerived

A remote attacker could crash the application by dereferencing a null pointer by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 3.3% exploitation probability (EPSS)

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AnalysisAI

The EAP-pwd implementation in hostapd (EAP server) before 2.8 and wpa_supplicant (EAP peer) before 2.8 does not validate fragmentation reassembly state properly for a case where an unexpected. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. The EAP-pwd implementation in hostapd (EAP server) before 2.8 and wpa_supplicant (EAP peer) before 2.8 does not validate fragmentation reassembly state properly for a case where an unexpected fragment could be received. This could result in process termination due to a NULL pointer dereference (denial of service). This affects eap_server/eap_server_pwd.c and eap_peer/eap_pwd.c. Affected products include: W1.Fi Hostapd, W1.Fi Wpa Supplicant. Version information: before 2.8.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionNVD

The EAP-pwd implementation in hostapd (EAP server) before 2.8 and wpa_supplicant (EAP peer) before 2.8 does not validate fragmentation reassembly state properly for a case where an unexpected fragment could be received. This could result in process termination due to a NULL pointer dereference (denial of service). This affects eap_server/eap_server_pwd.c and eap_peer/eap_pwd.c.

Threat Intelligence Overview

EPSS Score
3.3%
Top 13% exploitable
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 3.3%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

33
Low Medium High Critical
KEV: 0
EPSS: +3
CVSS: +30
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:a:w1.fi:hostapd:*:*:*:*:*:*:*:*
cpe:2.3:a:w1.fi:wpa_supplicant:*:*:*:*:*:*:*:*
CVE-2017-13082 HIGH POC
8.1 Oct 17

Wi-Fi Protected Access (WPA and WPA2) that supports IEEE 802.11r allows reinstallation of the Pairwise Transient Key (PT

CVE-2019-9499 HIGH
8.1 Apr 17

The implementations of EAP-PWD in wpa_supplicant EAP Peer, when built against a crypto library missing explicit validati

CVE-2019-9498 HIGH
8.1 Apr 17

The implementations of EAP-PWD in hostapd EAP Server, when built against a crypto library missing explicit validation on

CVE-2019-9497 HIGH
8.1 Apr 17

The implementations of EAP-PWD in hostapd EAP Server and wpa_supplicant EAP Peer do not validate the scalar and element

CVE-2014-3686 MEDIUM
6.8 Oct 16

wpa_supplicant and hostapd 0.7.2 through 2.2, when running with certain configurations and using wpa_cli or hostapd_cli

CVE-2016-4476 HIGH
7.5 May 09

hostapd 0.6.7 through 2.5 and wpa_supplicant 0.6.7 through 2.5 do not reject \n and \r characters in passphrase paramete

CVE-2020-12695 HIGH
7.5 Jun 08

The Open Connectivity Foundation UPnP specification before 2020-04-17 does not forbid the acceptance of a subscription r

CVE-2019-9496 HIGH
7.5 Apr 17

An invalid authentication sequence could result in the hostapd process terminating due to missing state validation steps

CVE-2026-58374 HIGH
7.1 Jun 30

Denial of service in hostapd 2.11 through pre-2.12 development snapshots (built with CONFIG_IEEE80211BE) lets an unauthe

CVE-2017-13084 MEDIUM
6.8 Oct 17

Wi-Fi Protected Access (WPA and WPA2) allows reinstallation of the Station-To-Station-Link (STSL) Transient Key (STK) du

CVE-2017-13077 MEDIUM
6.8 Oct 17

Wi-Fi Protected Access (WPA and WPA2) allows reinstallation of the Pairwise Transient Key (PTK) Temporal Key (TK) during

CVE-2017-13086 MEDIUM
6.8 Oct 17

Wi-Fi Protected Access (WPA and WPA2) allows reinstallation of the Tunneled Direct-Link Setup (TDLS) Peer Key (TPK) duri

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