CVE-2026-11517: UTT HiPER 2610G Buffer Overflow in DNS Configuration

Technical summary

The vulnerability resides in the strcpy function within the /goform/formConfigDnsFilterGlobal endpoint. The GroupName parameter is processed without proper bounds checking, allowing an authenticated attacker to craft input that exceeds the target buffer's capacity. This classic buffer overflow condition (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer; CWE-120: Buffer Copy without Checking Size of Input) can overwrite adjacent memory regions containing function pointers or return addresses, leading to denial of service or arbitrary code execution with the privileges of the affected process.

Business impact

Compromise of UTT HiPER 2610G devices impacts network infrastructure, potentially disrupting DNS filtering and gateway functionality. An authenticated attacker could deny service, alter DNS routing rules to redirect traffic, or gain deeper access to the network. Organizations relying on these devices for security perimeter control face operational downtime and potential data exfiltration vectors. The authentication requirement raises the barrier to opportunistic exploitation but remains a significant risk in environments where device access is shared or where account credentials have been compromised elsewhere.

Affected systems

UTT HiPER 2610G devices with firmware version 3.0.0-171107 and all earlier versions are affected. Organizations should audit deployed UTT HiPER 2610G units to confirm current firmware versions. Verify against the vendor advisory for confirmed patched versions and the scope of affected models.

Exploitability

The vulnerability requires authenticated access, which substantially reduces attack surface compared to unauthenticated remote exploits. However, the public disclosure of the flaw means that exploitation techniques are available to threat actors, removing the benefit of obscurity. An attacker must first obtain valid credentials (via credential theft, social engineering, or weak default passwords) before leveraging the buffer overflow. Once authenticated, the attack is trivial to execute and does not require user interaction or special network conditions (CVSS vector: AV:N/AC:L/PR:L).

Remediation

Vendors must release firmware patches that implement secure string handling (e.g., strncpy or strlcpy with explicit length checks) for the GroupName parameter and conduct bounds validation on all user inputs to the DNS filter configuration endpoint. Organizations should apply patches as soon as vendor updates are released and verified in non-production environments. Until patches are available, restrict administrative access to these devices via network segmentation, strong authentication, and access control lists.

Patch guidance

Monitor the UTT vendor advisory for firmware update releases addressing CVE-2026-11517. When patches become available, validate functionality in a lab environment before deploying to production. Verify the patched firmware version against the vendor's official release notes to confirm the specific build includes this fix. Maintain backups of current configurations before applying firmware updates. After patching, restart affected devices during a maintenance window and confirm DNS filtering operations resume normally.

Detection guidance

Monitor authentication logs for unusual or failed login attempts to UTT HiPER 2610G management interfaces. Inspect HTTP POST requests to /goform/formConfigDnsFilterGlobal for abnormally long or suspicious GroupName parameter values that may indicate buffer overflow attempts. Log device crashes or unexpected reboots as potential exploitation indicators. Intrusion detection systems should be configured to flag payloads characteristic of buffer overflow attacks against known vulnerable endpoints. Correlate security events with firmware version inventory to identify vulnerable instances.

Why prioritize this

Despite the authentication requirement, the HIGH CVSS score (8.8), public exploit disclosure, and potential for complete compromise (confidentiality, integrity, and availability impact) warrant rapid remediation. Authenticated attackers pose genuine risk in many operational environments. The combination of known attack techniques and easy exploitation path justifies expedited patching and access control hardening.

Risk score, explained

The CVSS 3.1 score of 8.8 (HIGH) reflects high impact across all three security dimensions (confidentiality, integrity, availability) with low complexity exploitation and low attack complexity. The authentication prerequisite (PR:L) prevents a 9.0+ critical rating. The network-accessible attack vector, coupled with public disclosure, elevates operational risk despite the authentication gate. Organizations should treat this as a high-priority remediation target.

Frequently asked questions