Published:2015/10/16  Last Updated:2015/10/16

Avast vulnerable to directory traversal


Avast contains a directory traversal vulnerability.

Products Affected

  • Avast with Virus Definition ID prior to 150918-0


Avast contains an issue in processing archive files, which may result in a directory traversal (CWE-22) vulnerability.
When an archive file such as zip is detected as containing a virus and the included virus file is being moved or deleted, the operation is done to the file path inside the archive file.


When an archive such as zip is scanned and a file in the archive is detected to be a virus, and either the move or delete option is selected, the operation is performed against the file path specified within the archive file.


Update the Virus Definition
Update the Virus Definition file to the latest version according to the information provided by the developer.

According to the developer, the vulnerable code is included in Virus Definition and ID 150918-0 addressed the issue.

Vendor Status

Vendor Link
AVAST Software s.r.o. Virus Update History


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2015.10.16 (CVSS Base Metrics)

What is CVSS?

Measures Severity Description
Access Vector(AV) Local (L) Adjacent Network (A) Network (N) A vulnerability exploitable with network access means the vulnerable software is bound to the network stack and the attacker does not require local network access or local access. Such a vulnerability is often termed "remotely exploitable".
Access Complexity(AC) High (H) Medium (M) Low (L) The access conditions are somewhat specialized.
Authentication(Au) Multiple (M) Single (S) None (N) Authentication is not required to exploit the vulnerability.
Confidentiality Impact(C) None (N) Partial (P) Complete (C) There is no impact to the confidentiality of the system.
Integrity Impact(I) None (N) Partial (P) Complete (C) Modification of some system files or information is possible, but the attacker does not have control over what can be modified, or the scope of what the attacker can affect is limited.
Availability Impact(A) None (N) Partial (P) Complete (C) There is no impact to the availability of the system.

Base Score:4.3


Ryohei Koike of Sakura Information Systems Co., Ltd. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2015-5662
JVN iPedia JVNDB-2015-000160