MEDIUM
CVE-2021-27506
NVD-CWE-noinfoPublished: March 19, 2021· Updated: Jun 17, 2026
5.5
CVSS v3.1
Official Description
The ClamAV Engine (version 0.103.1 and below) component embedded in Storsmshield Network Security (SNS) is subject to DoS in case of parsing of malformed png files. This affect Netasq versions 9.1.0 to 9.1.11 and SNS versions 1.0.0 to 4.2.0. This issue is fixed in SNS 3.7.19, 3.11.7 and 4.2.1.
Technical Analysis
CVE-2021-27506 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Affected Vendors & Products
clamav1 product(s)
clamav
netasq_project1 product(s)
netasq
stormshield1 product(s)
stormshield network security
Source: NVD CPE · 3 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (4)
→
https://advisories.stormshield.eu/2021-003/Broken Link · Vendor Advisory
→
→
https://advisories.stormshield.eu/2021-003/Broken Link · Vendor Advisory
→
Quick Facts
CVE IDCVE-2021-27506
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected3 vendor(s)
PublishedMar 19, 2021
Related CVEs (NVD-CWE-noinfo)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-27506 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.