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Rtl819x Jungle Software Development KitApplication · Realtek

CVE-2023-34435

HIGH · 7.2 CVSS v3.1 Published 2024-07-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable 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
A firmware update vulnerability exists in the boa formUpload functionality of Realtek rtl819x Jungle SDK v3.4.11. A specially crafted network packets can lead to arbitrary firmware update. An attacker can provide a malicious file to trigger this vulnerability.

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 · moderate confidence

A firmware update vulnerability exists in the boa web server's formUpload function within the Realtek rtl819x Jungle SDK v3.4.11. The vulnerability allows an unauthenticated attacker to send specially crafted network packets containing a malicious firmware file, which gets written to device flash memory without proper validation. This enables complete device compromise through malicious firmware injection.

MitigationImplement proper authentication and cryptographic signature verification for all firmware upload requests in the formUpload functionality. Additionally, add input validation to verify the uploaded file is a legitimate firmware image before accepting it.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Rtl819x Jungle Software Development KitApplication
Affected:= 3.4.11
Wbr 6013 FirmwareOperating system
Affected:= rer4_a_v3411b_2t2r_lev_09_170623

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
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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. Identify the SDK or firmware version in use
    Check the device's firmware version string or SDK version by reviewing the firmware binary, bootloader configuration, or device info page. For Level1 Wbr 6013, look for version rer4_a_v3411b_2t2r_lev_09_170623.
    Affected if The device runs Realtek rtl819x Jungle SDK v3.4.11 or Level1 Wbr 6013 firmware rer4_a_v3411b_2t2r_lev_09_170623
  2. Confirm the boa web server is present
    Identify if the boa web server binary exists on the firmware filesystem by examining the firmware image or accessing /proc/mounts and /bin/ on the live device.
    Affected if The boa web server binary is present and running on the device
  3. Verify the formUpload function is compiled in
    Inspect the boa binary or its configuration to determine if the formUpload handler is enabled. This may require binwalk or strings analysis of the firmware binary, or checking the web server configuration for upload-related CGI endpoints.
    Affected if The formUpload CGI handler is present in the boa web server build
  4. Check if firmware upload is accessible without authentication
    Attempt to access the firmware upload endpoint (typically /formUpload or similar) without providing credentials, or review the web server access control configuration to determine if upload endpoints are protected.
    Affected if The firmware upload endpoint is accessible without authentication or any access control enforcement
  5. Verify no cryptographic signature verification exists for uploads
    Analyze the firmware upload handling code (if accessible) or capture a firmware upload request to inspect whether any signature or integrity verification is performed before the file is written to flash.
    Affected if No signature verification or integrity check is performed on uploaded firmware files before writing to flash

A device is affected if it uses the Realtek rtl819x Jungle SDK v3.4.11 or Level1 Wbr 6013 firmware rer4_a_v3411b_2t2r_lev_09_170623, runs the boa web server with formUpload enabled, and allows unauthenticated firmware uploads without signature verification.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement proper authentication and cryptographic signature verification for all firmware upload requests in the formUpload functionality. Additionally, add input validation to verify the uploaded file is a legitimate firmware image before accepting it.

Fix this in Rtl819x Jungle Software Development Kit Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
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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-2023-34435 in production — separate from our analysis above.

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What this is

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What belongs here
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