CVE-2021-35395
Realtek AP-Router SDK Buffer Overflow Vulnerabilit - [Actively Exploited]
Description
Realtek Jungle SDK version v2.x up to v3.4.14B provides an HTTP web server exposing a management interface that can be used to configure the access point. Two versions of this management interface exists: one based on Go-Ahead named webs and another based on Boa named boa. Both of them are affected by these vulnerabilities. Specifically, these binaries are vulnerable to the following issues: - stack buffer overflow in formRebootCheck due to unsafe copy of submit-url parameter - stack buffer overflow in formWsc due to unsafe copy of submit-url parameter - stack buffer overflow in formWlanMultipleAP due to unsafe copy of submit-url parameter - stack buffer overflow in formWlSiteSurvey due to unsafe copy of ifname parameter - stack buffer overflow in formStaticDHCP due to unsafe copy of hostname parameter - stack buffer overflow in formWsc due to unsafe copy of 'peerPin' parameter - arbitrary command execution in formSysCmd via the sysCmd parameter - arbitrary command injection in formWsc via the 'peerPin' parameter Exploitability of identified issues will differ based on what the end vendor/manufacturer did with the Realtek SDK webserver. Some vendors use it as-is, others add their own authentication implementation, some kept all the features from the server, some remove some of them, some inserted their own set of features. However, given that Realtek SDK implementation is full of insecure calls and that developers tends to re-use those examples in their custom code, any binary based on Realtek SDK webserver will probably contains its own set of issues on top of the Realtek ones (if kept). Successful exploitation of these issues allows remote attackers to gain arbitrary code execution on the device.
INFO
Published Date :
Aug. 16, 2021, 12:15 p.m.
Last Modified :
Aug. 8, 2023, 2:21 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
3.9
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
Realtek AP-Router SDK HTTP web server �boa� contains a buffer overflow vulnerability due to unsafe copies of some overly long parameters submitted in the form that lead to denial-of-service (DoS).
Apply updates per vendor instructions.
Public PoC/Exploit Available at Github
CVE-2021-35395 has a 2 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-35395.
| URL | Resource |
|---|---|
| https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain | Exploit Third Party Advisory |
| https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en | Patch Vendor Advisory |
| https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf | Patch |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Yet Another Boa Webserver Fork
Makefile Shell M4 C
Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.
cisa-kev vulnerability 0day cisa exploits
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-35395 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-35395 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Aug. 26, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:C/I:C/A:C) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain No Types Assigned https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain Exploit, Third Party Advisory Changed Reference Type https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en No Types Assigned https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en Patch, Vendor Advisory Changed Reference Type https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf No Types Assigned https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf Patch Added CWE NIST CWE-787 Added CWE NIST CWE-77 Added CPE Configuration OR *cpe:2.3:a:realtek:realtek_jungle_sdk:*:*:*:*:*:*:*:* versions from (including) 2.0 up to (including) 3.4.14b
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-35395 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-35395
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
96.63 }} -0.10%
score
0.99680
percentile