CVE-2022-23303 Overview
CVE-2022-23303 is a side channel vulnerability affecting the Simultaneous Authentication of Equals (SAE) implementations in hostapd and wpa_supplicant, two critical components used for wireless network authentication. The vulnerability arises from observable cache access patterns during cryptographic operations, which can be exploited by attackers to recover sensitive authentication information. This issue is notably an incomplete fix for a previously disclosed vulnerability, CVE-2019-9494.
Critical Impact
Attackers can leverage cache-based side channel attacks to potentially recover WPA3-SAE authentication credentials, compromising the security of wireless networks protected by the affected software.
Affected Products
- w1.fi hostapd (versions before 2.10)
- w1.fi wpa_supplicant (versions before 2.10)
- Fedora Project Fedora 35
Discovery Timeline
- 2022-01-17 - CVE-2022-23303 published to NVD
- 2025-11-03 - Last updated in NVD database
Technical Details for CVE-2022-23303
Vulnerability Analysis
The vulnerability exists in the SAE (Simultaneous Authentication of Equals) protocol implementation, which is the key exchange mechanism used in WPA3-Personal networks. SAE relies on password-authenticated key exchange based on the Dragonfly handshake. The implementation in affected versions of hostapd and wpa_supplicant exhibits observable differences in cache access patterns during the password encoding process.
This cache timing side channel (CWE-203: Observable Discrepancy) allows an attacker with local access or the ability to monitor cache behavior to infer information about the password being used during the SAE handshake. The issue stems from the fact that cryptographic operations do not execute in constant time, creating measurable timing differences that correlate with secret values.
Root Cause
The root cause is the use of non-constant-time operations during the SAE password element derivation process. When the implementation performs elliptic curve operations as part of the Dragonfly key exchange, the cache access patterns vary depending on the secret password value. This creates an observable discrepancy that an attacker can exploit through cache timing analysis techniques such as Flush+Reload or Prime+Probe attacks.
This vulnerability represents an incomplete fix for CVE-2019-9494, indicating that previous mitigation attempts did not fully address all code paths where timing variations could leak information about the password.
Attack Vector
The attack vector is network-based, requiring the attacker to either be on the same physical system (for local cache attacks) or to have network proximity to observe multiple authentication attempts. The attacker can perform the following:
- Monitor cache timing during SAE handshake operations
- Collect timing measurements across multiple authentication attempts
- Apply statistical analysis to correlate cache access patterns with password characters
- Potentially recover the WPA3-SAE password through iterative analysis
The attack does not require any privileges or user interaction, making it particularly dangerous in environments where attackers can establish prolonged observation of the authentication process.
Detection Methods for CVE-2022-23303
Indicators of Compromise
- Unusual timing patterns during WPA3-SAE authentication handshakes
- Repeated authentication attempts from the same or similar client MAC addresses
- Abnormal process behavior monitoring cache access on systems running hostapd or wpa_supplicant
- Evidence of Flush+Reload or Prime+Probe side channel attack tools on local systems
Detection Strategies
- Monitor for multiple failed or repeated SAE authentication attempts that may indicate timing measurement collection
- Implement process monitoring on systems running hostapd or wpa_supplicant to detect unauthorized cache probing
- Review system logs for unusual authentication patterns or timing anomalies
- Deploy runtime application self-protection (RASP) solutions capable of detecting side channel attack techniques
Monitoring Recommendations
- Enable verbose logging on hostapd and wpa_supplicant to capture authentication events
- Implement network monitoring to detect unusual wireless client behavior near access points
- Deploy endpoint detection solutions on systems hosting wireless authentication services
- Establish baselines for normal authentication timing to identify statistical outliers
How to Mitigate CVE-2022-23303
Immediate Actions Required
- Upgrade hostapd to version 2.10 or later immediately
- Upgrade wpa_supplicant to version 2.10 or later immediately
- Apply distribution-specific security patches (Fedora, Debian, Gentoo packages available)
- Review wireless network segmentation to limit potential attack surface
Patch Information
The vulnerability is addressed in hostapd version 2.10 and wpa_supplicant version 2.10. The fix implements constant-time operations for the SAE password encoding process to eliminate observable cache access pattern differences. Organizations should consult the w1.fi Security Advisory for detailed patch information.
Distribution-specific patches are available:
Workarounds
- Implement additional network segmentation to isolate wireless infrastructure from untrusted networks
- Consider using WPA3-Enterprise with certificate-based authentication as an alternative to SAE password-based authentication
- Restrict physical access to systems running hostapd or wpa_supplicant to reduce local cache attack risk
- Monitor for and block known side channel attack tools at the endpoint level
# Check current hostapd version
hostapd -v
# Check current wpa_supplicant version
wpa_supplicant -v
# Update packages on Debian/Ubuntu systems
sudo apt update && sudo apt upgrade hostapd wpa_supplicant
# Update packages on Fedora systems
sudo dnf update hostapd wpa_supplicant
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
