CVE-2021-35395
Exploitation confirmed. First attested on 2021-11-03 by CISA-ADP, CISA KEV, GCVE · kevintel, GCVE · shadowserver.
- Published2021-08-16
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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.
Timeline
dates in UTCObserved activity
isMalicious corpus · updated 2026-11-03 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-35395?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-35395?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 3.4 | ≥ 2.0, ≤ 3.4.14b | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- CISA’s required action: Apply updates per vendor instructions.due 2021-11-17
Advisories and patches
- www.realtek.comPatch · Vendor Advisory
- www.realtek.comPatch
Detection
read 2026-11-02 22:42 UTC- Nuclei template
- available ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
- Metasploit modules
- none listed Metasploit Framework
CISA Known Exploited Vulnerability
- Date Added
- 2021-11-03
- Patch Due Date
- 2021-11-17
- Ransomware Use
- Unknown
- Required Action
- Apply updates per vendor instructions.
Sources
- CISA KEVKEV entry2021-11-03
- ENISA EUVDexploitation2021-11-032021-11-03
- GCVEexploitation2021-11-03
- CISA-ADPSSVC decisionactive2025-02-04
- OpenCVESSVC decisionactive—
- CISA-ADPCVSS 3.19.82025-02-04
- NVDCVSS 3.19.8read 2026-10-23
- NVDCVSS 2.010read 2026-10-23
- FIRST EPSSEPSS score98.1 %read 2026-11-02
- ProjectDiscoverydetectionread 2026-11-02
- GitHub Advisoriesadvisory—
Identifiers
- EUVD-2021-22038same flawENISA EUVD · LicenseRef-ENISA-legal-notice
- GHSA-qrv5-8v43-rrgfsame flawGitHub Advisory Database · CC-BY-4.0
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-08-16
- Last Modified
- 2026-06-17
- NVD status
- Analyzed
- GitHub Advisory
- GHSA-qrv5-8v43-rrgf
Frequently asked questions
What is CVE-2021-35395?
Is CVE-2021-35395 actively exploited?
What is the CVSS score for CVE-2021-35395?
Hear about the next vulnerability in your software
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
No credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- For a threat intelligence platform: malware, C2 and ransomware indicators over STIX/TAXII.
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.
Sources for this record
- CISA KEV · CC0-1.0 (cisagov/kev-data)
- CVE Program · CVE Program Terms of Use
- ENISA EU Vulnerability Database · ENISA legal notice §1.2 (reproduction authorised, provided the source is acknowledged)
- FIRST EPSS · EPSS terms of use (free use, attribution requested)
- GCVE · GCVE dump terms (preserve source attribution)
- GitHub Advisory Database · CC-BY-4.0 · GHSA-qrv5-8v43-rrgf
- Nuclei templates · MIT
- NVD · Public domain (17 U.S.C. § 105) for NVD-authored data; third-party content under its own terms
- OpenCVE · OpenCVE terms of service · terms restrict redistribution
- CISA Vulnrichment · CC0-1.0