CVE-2025-59609: Qualcomm MBSSID Information Disclosure (MEDIUM 5.5)

Technical summary

The vulnerability stems from insufficient bounds checking when parsing MBSSID elements in 802.11 advertisement frames. MBSSID is a Wi-Fi feature enabling multiple basic service sets to share a single MAC address. When an advertisement frame contains a malformed MBSSID element shorter than the parser expects, the code reads beyond the allocated buffer boundary into adjacent memory (CWE-126: Out-of-bounds read). This uninitialized memory may contain session keys, authentication tokens, or other sensitive wireless protocol data. The parsing logic fails to validate element length before dereferencing, allowing an authenticated attacker within Wi-Fi range to trigger the disclosure by transmitting crafted frames. The vulnerability affects the wireless driver stacks across Qualcomm's FastConnect, CSR, WCN, and audio codec ecosystems.

Business impact

Organizations deploying Qualcomm-based wireless equipment—including enterprise access points, 5G fixed wireless CPE, embedded IoT gateways, and audio peripherals—face potential credential leakage and session compromise. An attacker with network access could passively extract encryption material or authentication tokens without direct user consent, then pivot to secondary attacks on protected resources. The broad product portfolio affected means exposure spans enterprise networking, consumer IoT, automotive telematics, and industrial wireless systems. While the attack requires authentication and user interaction, the low barrier to entry once inside a trusted network makes this a meaningful risk for organizations with shared or semi-open wireless infrastructure.

Affected systems

Qualcomm's affected product family is extensive and includes: the 5G Fixed Wireless Access Platform (CPE devices), AR8035, CSR8811, FastConnect 6700/6900 (enterprise Wi-Fi modules), SXR2250P (XR platform), WCD9340–9395 series (audio codecs with wireless integration), WCN3950/3988 (legacy Wi-Fi controllers), WCN6650/6755 (current-generation Wi-Fi 6/6E modules), and WSA8810 (speaker chipset). Both firmware and hardware SKUs are listed, meaning patching may require firmware updates, driver updates, or both depending on deployment model. Verify your specific product versions against the vendor security advisory to determine applicable remediation.

Exploitability

Exploitation requires three conditions: (1) network proximity to a Qualcomm device, (2) valid Wi-Fi credentials or authenticated network access, and (3) successful triggering of user interaction or specific device state (per the CVSS attack vector notation AC:H and UI:R). These constraints reduce real-world exploitability compared to unauthenticated network flaws. An insider, rogue access point operator, or attacker on a compromised network segment could readily craft and inject malformed frames, but external exploitation is impractical. The vulnerability is not currently tracked in CISA's Known Exploited Vulnerabilities catalog, suggesting limited evidence of weaponization in the wild. However, the straightforward nature of the bug (malformed frame → buffer read) and its presence across so many firmware images make it likely to attract security researcher interest once patches ship.

Remediation

Qualcomm has issued firmware security updates addressing the buffer validation logic across affected product lines. Remediation involves patching the wireless driver and/or firmware to enforce proper MBSSID element length validation before memory access. Organizations should: (1) identify which Qualcomm products are deployed in their estate, (2) consult the Qualcomm Security Bulletin for applicable patch versions and release dates, (3) prioritize patching for devices in high-trust network segments or handling sensitive data, and (4) stage updates in test environments first given the breadth of affected hardware. Verify patch availability against the vendor advisory—not all product lines may have patches released simultaneously.

Patch guidance

Contact Qualcomm or your device manufacturer for the specific security update applicable to your product SKU. Updates typically arrive as firmware OTA push, driver package, or combined BSP release depending on your deployment model (embedded device, module on carrier board, or managed endpoint). Test patches in a staging environment with representative traffic patterns before production rollout. For FastConnect and WCN modules integrated into larger systems (routers, gateways, IoT hubs), coordinate with your system vendor to ensure firmware compatibility and that the patch does not introduce regressions. Document patch dates and versions applied for compliance audit trails. Given the AC:H (attack complexity high) rating, patching can be scheduled outside emergency windows but should not be indefinitely deferred.

Detection guidance

Detection in operational networks is challenging without anomalous behavior indicators. Network-based detection: monitor for malformed Wi-Fi beacons or probe responses with truncated MBSSID elements using packet inspection tools or Wi-Fi IDS appliances. Endpoint-based detection: enable driver-level logging on affected devices and alert on memory access exceptions or unhandled exception vectors in the wireless driver, though this may impose performance overhead. Log correlation: track unexpected Wi-Fi authentication failures or session drops on Qualcomm devices correlating to malformed frame timestamps. Given the information disclosure nature (not immediate system crash), detection via crash telemetry alone is unreliable. Prioritize detection tuning for high-value network segments post-patch; pre-patch detection efforts are best coupled with network segmentation to limit attacker reach.

Why prioritize this

Despite its MEDIUM CVSS score, CVE-2025-59609 merits relatively high priority due to: (1) breadth of affected Qualcomm product ecosystem—you likely use multiple affected components, (2) information disclosure of authentication/session material is particularly damaging in enterprise contexts, (3) the vulnerability sits at the wireless driver layer where it can cascade into multiple upstream applications, (4) no known exploit complexity barriers reduce the attack surface once internal network access is obtained, and (5) patches are in flight but not yet universal across all product lines. Organizations with high-security-requirement facilities (banking, healthcare, research) or those handling confidential communications should prioritize this within 30–60 days. Lower-urgency deployments (consumer IoT, non-critical access points) can follow standard patching cadence.

Risk score, explained

The CVSS 5.5 MEDIUM score reflects the attack complexity (AC:H, requiring specific conditions and user interaction) and limited scope of the confidentiality impact (C:L). However, the score does not fully capture the breadth of the vendor ecosystem or the privileged nature of wireless authentication data. The score weights network accessibility (AV:N) and moderate integrity/availability leakage (I:L, A:L), but downweights the impact due to required authentication (PR:L). For organizations running sensitive wireless infrastructure or IoT fleets, a locally elevated environmental score would be justified. The CVSS serves as a baseline; contextual risk assessment should consider your network architecture, asset criticality, and threat model.

Frequently asked questions