HOMEVULNERABILITIESCVE-2017-6420
MEDIUM

CVE-2017-6420

CWE-416Published: August 7, 2017· Updated: Jun 17, 2026

5.5
CVSS v3.1

Official Description

The wwunpack function in libclamav/wwunpack.c in ClamAV 0.99.2 allows remote attackers to cause a denial of service (use-after-free) via a crafted PE file with WWPack compression.

NVD Source

Technical Analysis

CVE-2017-6420 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.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected Vendors & Products

clamav1 product(s)
clamav
Source: NVD CPE · 1 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

PATCHhttps://github.com/vrtadmin/clamav-devel/commit/dfc00cd3301a42b571454b51a6102eecf58407bc
PATCHhttps://github.com/vrtadmin/clamav-devel/commit/dfc00cd3301a42b571454b51a6102eecf58407bc
ADVISORYhttps://github.com/varsleak/varsleak-vul/blob/master/clamav-vul/use-after-free/clamav-use-after-free-pe.md
ADVISORYhttps://github.com/varsleak/varsleak-vul/blob/master/clamav-vul/use-after-free/clamav-use-after-free-pe.md

All References (8)

→
https://bugzilla.clamav.net/show_bug.cgi?id=11798Permissions Required
→
https://github.com/varsleak/varsleak-vul/blob/master/clamav-vul/use-after-free/clamav-use-after-free-pe.mdThird Party Advisory
→
https://github.com/vrtadmin/clamav-devel/commit/dfc00cd3301a42b571454b51a6102eecf58407bcIssue Tracking · Patch · Third Party Advisory
→
https://security.gentoo.org/glsa/201804-16
→
https://bugzilla.clamav.net/show_bug.cgi?id=11798Permissions Required
→
https://github.com/varsleak/varsleak-vul/blob/master/clamav-vul/use-after-free/clamav-use-after-free-pe.mdThird Party Advisory
→
https://github.com/vrtadmin/clamav-devel/commit/dfc00cd3301a42b571454b51a6102eecf58407bcIssue Tracking · Patch · Third Party Advisory
→
https://security.gentoo.org/glsa/201804-16

Quick Facts

CVE IDCVE-2017-6420
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessCWE-416
CISA KEVNo
Affected1 vendor(s)
PublishedAug 7, 2017

Related CVEs (CWE-416)

CVE-2015-3075
10.0
CVE-2015-3059
10.0
CVE-2014-1512
10.0
CVE-2015-3053
10.0
CVE-2014-1563
10.0
CVE-2015-4448
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2017-6420 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.
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