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CVE-2018-6836: Wireshark: Denial of service

CVE-2018-6836 is rated critical with a CVSS v3.0 base score of 9.8 and affects Wireshark. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

The netmonrec_comment_destroy function in wiretap/netmon.c in Wireshark through 2.4.4 performs a free operation on an uninitialized memory address, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-763: Release of Invalid Pointer or Reference

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

Affected products

• Wireshark: up to and including 2.4.4

References

• https://code.wireshark.org/review/#/c/25660/
• https://code.wireshark.org/review/#/c/25660/2/wiretap/netmon.c
• https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=14397
• https://code.wireshark.org/review/gitweb?p=wireshark.git%3Ba=commit%3Bh=28960d79cca262ac6b974f339697b299a1e28fef