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Stack-based Buffer OverflowWeakness · CWE-121

CVE-2025-40634

CRITICAL · 9.2 CVSS v4.0 Published 2025-05-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stack-based buffer overflow vulnerability in the 'conn-indicator' binary running as root on the TP-Link Archer AX50 router, in firmware versions prior to 1.0.15 build 241203 rel61480. This vulnerability allows an attacker to execute arbitrary code on the device over LAN and WAN networks.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Stack-based buffer overflow in the 'conn-indicator' binary running as root on TP-Link Archer AX50 routers allows remote attackers to execute arbitrary code via LAN/WAN. The vulnerability affects firmware versions prior to 1.0.15 build 241203 rel61480.

MitigationUpdate router firmware to version 1.0.15 build 241203 rel61480 or later to patch the vulnerability. If the update is unavailable, minimize exposure by disabling WAN management interfaces and restricting LAN access.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model is TP-Link Archer AX50
    Access the router admin panel (typically at 192.168.0.1 or 192.168.1.1) and check the device model in System or Device Info settings, or look for the model number on the physical device label
    Affected if The device is not a TP-Link Archer AX50
  2. Check installed firmware version
    In the router admin panel, navigate to Status or System > Firmware Upgrade to view the current firmware version. Compare it against version 1.0.15 build 241203 rel61480
    Affected if Firmware version is earlier than 1.0.15 build 241203 rel61480 (e.g., 1.0.14, 1.0.13, or any build prior to 241203)
  3. Verify conn-indicator binary presence
    Access the router via SSH or telnet if enabled, then check for the binary at typical binary locations such as /usr/bin/conn-indicator or /sbin/conn-indicator using 'ls -la' command
    Affected if The conn-indicator binary exists on the device and is executable
  4. Assess network exposure
    Check if WAN management interfaces are enabled (under Advanced > Network > WAN Access Settings) and whether the router is directly exposed to WAN. Also verify if LAN-side services listening on all interfaces are accessible from external networks
    Affected if WAN management is enabled or the router is directly accessible from the internet on LAN/WAN interfaces

You are affected if you own a TP-Link Archer AX50 running firmware earlier than 1.0.15 build 241203 rel61480 with the conn-indicator binary present and network exposure via LAN or WAN interfaces.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update router firmware to version 1.0.15 build 241203 rel61480 or later to patch the vulnerability. If the update is unavailable, minimize exposure by disabling WAN management interfaces and restricting LAN access.

Recommended fix Moderate confidence

TP-Link Archer AX50 firmware 1.0.15 build 241203 rel61480 or later

  1. 1. Identify the current firmware version of the TP-Link Archer AX50 router by accessing the web management interface and navigating to System > Firmware Upgrade or similar.
  2. 2. Navigate to the official TP-Link support website and download the firmware version 1.0.15 build 241203 rel61480 (or a later version if available).
  3. 3. In the router's web management interface, locate the firmware upgrade section and upload the downloaded firmware file.
  4. 4. Wait for the upgrade process to complete - do not power off the router during the firmware update.
  5. 5. After the router reboots, verify the new firmware version is installed and confirm the vulnerability is remediated.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-40634 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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