CVE-2026-18642 Overview
CVE-2026-18642 is a deserialization of untrusted data vulnerability [CWE-502] affecting TUBITAK BILGEM Software Technologies Research Institute's eta-otp-lock product. The flaw allows object injection when the application processes attacker-controlled serialized data. All versions before 1.0.4 are affected.
Successful exploitation requires local access and user interaction. An attacker who convinces a user to open or process a crafted serialized object can achieve code execution in the context of the target process. The vulnerability impacts confidentiality, integrity, and availability.
Critical Impact
Object injection through untrusted deserialization can lead to arbitrary code execution on the affected host, compromising the one-time-password lock component and any secrets it protects.
Affected Products
- TUBITAK BILGEM eta-otp-lock versions before 1.0.4
Discovery Timeline
- 2026-08-03 - CVE-2026-18642 published to NVD
- 2026-08-03 - Last updated in NVD database
Technical Details for CVE-2026-18642
Vulnerability Analysis
The vulnerability is classified as insecure deserialization mapped to [CWE-502]. The eta-otp-lock component reconstructs objects from serialized input without validating the type or origin of the incoming stream. Attackers can craft a serialized payload that, when deserialized, instantiates unintended classes or invokes gadget chains during object reconstruction.
Because the attack vector is local and requires user interaction, exploitation typically involves delivering a malicious serialized file or clipboard content that the victim opens with the vulnerable application. Once deserialized, the payload executes attacker-supplied logic with the privileges of the running process.
The issue affects a security-sensitive product responsible for OTP lock functionality, meaning code execution here can expose authentication secrets, tamper with lock state, or disable protective controls.
Root Cause
The root cause is the absence of input validation and type filtering during deserialization. Serialized data from untrusted sources is passed directly to a deserialization routine that trusts the embedded class metadata. No allowlist of permitted classes or integrity check is applied before reconstruction.
Attack Vector
An attacker crafts a malicious serialized object containing a gadget chain that triggers side effects during deserialization. The attacker delivers the payload to a local user, for example as a file, configuration import, or shared resource. When the user opens the payload with eta-otp-lock, deserialization runs the gadget chain and executes arbitrary code.
Refer to the Siber Güvenlik Notification TR-26-0730 for vendor-provided technical details.
Detection Methods for CVE-2026-18642
Indicators of Compromise
- Unexpected child processes spawned by the eta-otp-lock executable, particularly script interpreters or shells.
- Creation or modification of serialized data files (.bin, .dat, or vendor-specific formats) in user-writable directories immediately before eta-otp-lock launches.
- Outbound network connections initiated by the eta-otp-lock process to unknown hosts.
Detection Strategies
- Monitor process lineage for eta-otp-lock and alert when it spawns interpreters such as cmd.exe, powershell.exe, bash, or python.
- Inspect file open events for serialized payloads originating from email attachments, downloads, or removable media.
- Baseline the normal file and network behavior of the application and alert on deviations.
Monitoring Recommendations
- Enable endpoint telemetry that captures process creation, command-line arguments, and parent-child relationships.
- Log file writes to the eta-otp-lock working directory and correlate with subsequent process launches.
- Track version deployment across the fleet to confirm all installations are at 1.0.4 or later.
How to Mitigate CVE-2026-18642
Immediate Actions Required
- Upgrade eta-otp-lock to version 1.0.4 or later on all affected systems.
- Inventory endpoints running vulnerable versions using software asset management tooling.
- Restrict which users can open serialized data files with the vulnerable application until patching completes.
Patch Information
The vendor released a fix in eta-otp-lock version 1.0.4. Consult the Siber Güvenlik Notification TR-26-0730 advisory for the vendor's remediation guidance and download instructions.
Workarounds
- Block execution of eta-otp-lock versions prior to 1.0.4 using application control policies.
- Train users to avoid opening untrusted serialized files or configuration imports delivered by email or messaging platforms.
- Apply least-privilege principles so that the account running eta-otp-lock cannot modify sensitive system resources.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
