CVE-2021-39509
High PUBLISHEDAn issue was discovered in D-Link DIR-816 DIR-816A2_FWv1.10CNB05_R1B011D88210 The HTTP request parameter is used in the handler function of...
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
An issue was discovered in D-Link DIR-816 DIR-816A2_FWv1.10CNB05_R1B011D88210 The HTTP request parameter is used in the handler function of /goform/form2userconfig.cgi route, which can construct the user name string to delete the user function. This can lead to command injection through shell metacharacters.
- CVE Published
- Aug 24, 2021
- Exploitation Reported
- Aug 24, 2021
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- dlink.com/en/security-bulletin dlink.com · CVE Record https://www.dlink.com/en/security-bulletin/
- GitHub — doudoudedi/main-DIR-816_A2_Command-injection github.com · CVE Record https://github.com/doudoudedi/main-DIR-816_A2_Command-injection/blob/...
- GitHub — doudoudedi/main-DIR-816_A2_Command-injection github.com · CVE Record https://github.com/doudoudedi/main-DIR-816_A2_Command-injection
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2021-08-24 18:52 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:L/Au:N/C:P/I:P/A:P
Exploitation Status
Exploited in the wild
Recorded 2021-08-24 18:52:26 UTC · The Shadowserver
Weaknesses (CWE)
-
Improper Neutralization of Special Elements used in a Command ('Command Injection')
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
18:52 UTC almost 5 years ago18:52 UTC · almost 5 years ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
18:52 UTC almost 5 years ago18:52 UTC · almost 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC almost 5 years ago00:00 UTC · almost 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-39509
{
"cve_id": "CVE-2021-39509",
"title": "An issue was discovered in D-Link DIR-816 DIR-816A2_FWv1.10CNB05_R1B011D88210...",
"affected_vendor": "D-Link",
"affected_product": "DIR-816",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}