CVE-2023-6549
Confirmed PUBLISHEDImproper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read
- CVE Published
- Jan 17, 2024
- Exploitation Reported
- Jan 17, 2024
- CVSS
- 8.2 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Cloud Software Group |
NetScaler ADC
|
14.1 to < 12.35 |
Affected |
| Cloud Software Group |
NetScaler ADC
|
13.1 to < 51.15 |
Affected |
| Cloud Software Group |
NetScaler ADC
|
13.0 to < 92.21 |
Affected |
| Cloud Software Group |
NetScaler ADC
|
13.1-FIPS to < 37.176 |
Affected |
| Cloud Software Group |
NetScaler ADC
|
12.1-FIPS to < 55.302 |
Affected |
| Cloud Software Group |
NetScaler ADC
|
12.1-NDcPP to < 55.302 |
Affected |
CVE References
- support.citrix.com/article/CTX584986/netscaler-adc-and-netscale... support.citrix.com · CVE Record https://support.citrix.com/article/CTX584986/netscaler-adc-and-netsca...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- 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 |
|---|---|
| CISA First | 2024-01-17 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-6549.yaml | Jun 01, 2026 |
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:N/I:L/A:H
Exploitation Status
Exploited in the wild
Recorded 2024-01-17 00:00:00 UTC · CISA
Proof of concept available
Recorded 2026-06-12 14:21:00 UTC · Nuclei Templates
Weaknesses (CWE)
-
Improper Restriction of Operations within the Bounds of a Memory Buffer
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-6549.yaml | Jun 01, 2026 |
| Nessus | https://www.tenable.com/plugins/nessus/189070 | Jun 02, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
14:21 UTC about 1 month ago14:21 UTC · about 1 month ago
Public PoC available
Public proof-of-concept code published
-
15:34 UTC about 2 months ago15:34 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
09:26 UTC about 1 year ago09:26 UTC · about 1 year ago
Nessus plugin available
Scanner coverage available
-
20:15 UTC over 2 years ago20:15 UTC · over 2 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 2 years ago00:00 UTC · over 2 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
11:01 UTC over 2 years ago11:01 UTC · over 2 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-2023-6549
{
"cve_id": "CVE-2023-6549",
"title": "Improper Restriction of Operations within the Bounds of a Memory Buffer in Ne...",
"affected_vendor": "Cloud Software Group",
"affected_product": "NetScaler ADC",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.2,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}