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- History
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- Tutorial
- Release Notes and Announcements
- Release Notes
- Public Image Release Notes
- Announcements
- Updating Some Image Pip Package Management Tools for CentOS 7
- CentOS 8 End of Maintenance
- Discontinuation of Support for SUSE Commercial Images
- Price Reduction in Selected Availability Zones
- OrcaTerm Proxy IP Addresses Updates
- Pay-as-you-go Price Adjustments for Standard S3 CVMs in the Silicon Valley Region
- Vulnerability repairing for Linux images
- Stopping supporting for Ubuntu 10.04 images
- Solution to Tomcat Start Failure on Ubuntu14.04
- Upgrading Virtio network card drive for Windows CVMs
- About Configuration of Security Group Port 53
- Windows Server 2003 System Images End of Support Announcement
- End of Support for Windows Server 2008 R2 Enterprise Edition SP1 64-bit System Images
- Product Introduction
- Purchase Guide
- Getting Started
- Operation Guide
- Operation Guide Overview
- Use Limits
- Convenience Features
- Instances
- Creating Instances
- Managing Instance Launch Template
- Batch Sequential Naming or Pattern String-Based Naming
- Logging In to Linux Instances
- Logging in to Windows instance
- Adjusting Configuration
- View Instance Details
- Renaming Instances
- Resetting Instance Password
- Managing Instance IPs
- Changing Instance Subnet
- Changing Security Group
- Conversion from Pay-As-You-Go to Monthly Subscription
- Searching for Instances
- Exporting Instance List
- Renewing Instances
- Starting Up Instances
- Shutting Down Instances
- Restarting Instances
- Reinstalling System
- Using Tencent Cloud Automation Tools to execute commands
- Terminating/Returning Instances
- Enabling Instance Termination Protection
- Instance Repossession or Recovering
- Spot Instances
- Querying the Repossession Status of a Spot Instance
- No Charges When Shut Down for Pay-as-You-Go Instances
- Managing Roles
- Enabling and Disabling Hyper-Threading
- Reserved Instances
- Images
- Migrating Servers
- Maintenance Tasks
- Cloud Disks
- Networking
- Security
- Security Groups
- Protection of Sensitive Operations
- Managing Login Password
- Managing SSH Keys
- Spread Placement Group
- Unblocking Port 25
- Tags
- Monitoring and Alarms
- Sample Console Configuration
- Best Practice
- Best Practices
- Choosing the CVM Model
- Setting up a Website
- Building an Environment
- Building a Website
- Building an Application
- Building a Visual GUI
- Data Backup
- Uploading Local Files to CVM
- Copying Local Files to CVMs
- Uploading Files from Windows to a Windows CVM via MSTSC
- Uploading Files from MacOS to Windows CVM Using MRD
- Uploading Files from Linux to Windows CVM using RDP
- Uploading files via WinSCP to a Linux CVM from Windows
- Uploading Files from Linux or MacOS to Linux CVM via SCP
- Uploading Files from Linux to a CVM Using FTP
- Uploading Files from Windows to a CVM Using FTP
- Other CVM Operations
- CVM Access to COS via a Private Network
- Best Practices for Boot Mode Legacy BIOS and UEFI
- Recovering Data on Linux CVMs
- Managing Disk Space on Windows CVMs
- Changing Kernel of a Linux Instance Manually
- Setting Up Windows-based AD Domain on a CVM
- Network Performance Test
- High-throughput Network Performance Test
- Using USB/IP to Share USB Devices in Linux
- Using RemoteFx to Redirect USB Devices in Windows
- Using AVX-512 Instructions to Accelerate AI Applications on CVM
- Building Tencent SGX Confidential Computing Environment
- Configuring Persistent Memory in M6p Instances
- Calling Cloud APIs via Python to Share Custom Images in Batches
- Operations Guide
- Initializing Data Disks
- Environment Configurations
- Installing Software
- User Data
- Work with Operating Systems
- System Activation
- System Updates
- System Shutdown
- Configuring High-performance Power Management
- Windows Recovery Mode
- Updating the Virtio ENI Driver
- Modifying SID
- Modifying VNC Resolution
- Ensuring Unique SIDs for CVMs Using Sysprep
- Use of the atop Monitoring Tools by Linux Instances
- Introduction to Linux Kernel Parameters
- Others
- Troubleshooting
- Instance-Related Failures
- CVM Login Failures
- Windows Instance Login Failures
- Windows Instance Login Failures
- An authentication error occurred when you tried to log in to a Windows instance remotely
- Failed to Reset the CVM Password or the CVM Password Is Invalid
- Connection to a Windows CVM through Remote Desktop was denied
- Requires network-level identity verification
- Problems occurred when you tried to log in to a Windows CVM remotely on Mac
- Failed to log in to a Windows CVM due to high CPU and memory usage
- Failed to connect to a remote computer through Remote Desktop
- Credentials Not Work
- Windows instance: no remote Desktop license server can provide license
- Remote Login Failure Due To Port Issues
- Linux Instance Login Failures
- Linux Instance Login Failures
- Unable to Log in to a Linux Instance via SSH Key
- Failing to log in to a Linux CVM due to high CPU and memory usage
- Remote Login Failure due to Port Issues
- VNC Login Error (Module is Unknown)
- VNC Login Error (Account Locked due to XXX Failed Logins)
- VNC Login Error (Login Failed with Correct Password)
- VNC or SSH Login Error (Permission Denied)
- Login Failure Due to /etc/fstab Configuration Errors
- sshd Configuration File Permissions
- Infinite Loop Call in /etc/profile
- Login Failure Due to Server Isolation
- Login Failure Due to High Bandwidth Occupation
- Remote Connect Failure Due to Security Group Settings
- Troubleshooting Linux Instance Issues via VNC and Rescue Mode
- Failed to shut down or restart a CVM
- Network Namespace Creation Failure
- Kernel and IO Issues
- Missing System bin or lib Soft Link
- Suspected Infection with Virus
- "no space left on device" Error During File Creation
- Linux CVM Memory Issues
- Network Related Failures
- Instance-Related Failures
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- Region APIs
- Instance APIs
- DescribeInstances
- DescribeInstanceFamilyConfigs
- DescribeZoneInstanceConfigInfos
- DescribeInstanceTypeConfigs
- DescribeInstancesOperationLimit
- DescribeInstanceVncUrl
- InquiryPriceRunInstances
- InquiryPriceResetInstance
- InquiryPriceResetInstancesType
- InquiryPriceResizeInstanceDisks
- RunInstances
- StartInstances
- RebootInstances
- StopInstances
- ResetInstance
- TerminateInstances
- ResetInstancesType
- ResizeInstanceDisks
- ResetInstancesPassword
- ModifyInstancesAttribute
- ModifyInstancesProject
- InquirePricePurchaseReservedInstancesOffering
- DescribeReservedInstancesConfigInfos
- DescribeInstancesStatus
- PurchaseReservedInstancesOffering
- Cloud Hosting Cluster APIs
- Placement Group APIs
- Image APIs
- Key APIs
- Security Group APIs
- Network APIs
- Instance Launch Template APIs
- Data Types
- Error Codes
- FAQs
- Related Agreement
- Glossary
VNC Login Error (Account Locked due to XXX Failed Logins)
Last updated: 2024-01-06 17:32:18
Error Description
The error “Account locked due to XXX failed logins” appears before I enter the login password.
Possible Reasons
This issue may be caused by the
pam_tally2.so configuration in /etc/pam.d/login file. For VNC login, /etc/pam.d/login is called for authentication, while pam_tally2.so indicates to automatically lock the user account temporarily or permanently after the specified number of consecutive failed logins. When an account is permanently locked, you need to unlock it manually.The login account will be locked when the number of consecutive failed logins exceeds the configured value. Note that the account may also be locked for brute force attacks.
pam_tally2 module.Parameter | Description |
deny=n | Lock the account if the number of consecutive failed logins exceeds n. |
lock_time=n | Lock the account for n seconds when the number of consecutive failed logins exceeds the limit |
un lock_time=n | Unlock the account automatically n seconds later |
no_lock_time | Do not use .fail_locktime field in /var/log/faillog |
magic_root | If the module is invoked by a root user (uid=0), the counter is not incremented. |
even_deny_root | The root user will be locked after deny=n consecutive failed logins. |
root_unlock_time=n | This parameter is required if even_deny_root is configured. It indicates how long the the root user is locked when the number of consecutive failed logins exceeds the limit. |
Solutions
1. Refer to troubleshooting procedure to access the login configuration file and temporarily comment out the configuration of the
pam_limits.so module.2. Find the reason why your account is locked, and improve your security policy.
Troubleshooting Procedure
1. Try to log in to Linux CVM via SSH key.
If the login succeeded, proceed to the next step.
If the login failed, try the single user mode.
2. Run the following command to view logs.
vim /var/log/secure
This file records the security information, mostly CVM login logs. You can check the error logs of 
pam_tally2 as shown below.
3. Run the following commands in sequence to open
/etc/pam.d directory and search for pam_tally2.cd /etc/pam.d
find . | xargs grep -ri "pam_tally2" -l
If the result similar to the following figure is returned, 
pam_tally2 is included in login file.
4. Run the following command to temporarily comment out the
pam_tally2.so configurations. Then you can log in normally.sed -i "s/.*pam_tally.*/#&/" /etc/pam.d/login
5. Check whether the account is locked due to misoperations or brute force attacks. In the later case, it is recommended to strengthen the security policy as follows:
Change the CVM password to a stronger password containing 12-16 characters, including uppercase letters, lowercase letters, special characters, and numbers. For more information, see Resetting Instance Password.
Delete unused CVM login accounts.
Change the default sshd port 22 to a less common port between 1024-65525. For more information, see Modifying the Default Remote Port of CVM.
Manage the associated security group rules to open only ports and protocols required by your business. For more information, see Adding Security Group Rules.
Close the port for internet access for core applications such as MySQL and Redis databases.
Install security software (such as CWPP agent), and configure real-time alarms to get notices about suspicious logins instantly.
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