Alwil Software Avast! Antivirus up to 4.7.869 LHA Archive heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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5.7$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Alwil Software Avast! Antivirus up to 4.7.869. This affects an unknown function of the component LHA Archive Handler. Such manipulation leads to heap-based overflow. This vulnerability is documented as CVE-2006-4626. Additionally, an exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Alwil Software Avast! Antivirus up to 4.7.869 (Anti-Malware Software) and classified as critical. Affected by this issue is an unknown part of the component LHA Archive Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. CVE summarizes:

Heap-based buffer overflow in alwil avast! Anti-virus Engine before 4.7.869 allows remote attackers to execute arbitrary code via a crafted LHA file that contains extended headers with file and directory names whose concatenation triggers the overflow.

The bug was discovered 07/04/2006. The weakness was released 09/08/2006 by Ryan Smith (Website). The advisory is shared for download at hustlelabs.com. This vulnerability is handled as CVE-2006-4626 since 09/07/2006. The attack needs to be done within the local network. No form of authentication is required for exploitation. Technical details are unknown but an exploit is available.

The exploit is available at hustlelabs.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 65 days. During that time the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 24281 (avast! Server Edition LHA Archive Extended-header Field Processing Overflow), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 115406 (Avast! Antivirus Engine Remote LHA Buffer Overflow Vulnerability).

Upgrading eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at avast.com. The best possible mitigation is suggested to be upgrading to the latest version. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 8977.

The vulnerability is also documented in the databases at X-Force (28824), Tenable (24281), SecurityFocus (BID 19903†), OSVDB (28612†) and Secunia (SA21794†). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 5.7

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 24281
Nessus Name: avast! Server Edition LHA Archive Extended-header Field Processing Overflow
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Patch: avast.com
TippingPoint: 🔍
PaloAlto IPS: 🔍

Timelineinfo

07/04/2006 🔍
09/07/2006 +65 days 🔍
09/07/2006 +0 days 🔍
09/07/2006 +0 days 🔍
09/07/2006 +0 days 🔍
09/08/2006 +1 days 🔍
09/08/2006 +0 days 🔍
09/08/2006 +0 days 🔍
09/11/2006 +2 days 🔍
09/19/2006 +8 days 🔍
02/06/2007 +140 days 🔍
06/16/2025 +6705 days 🔍

Sourcesinfo

Advisory: hustlelabs.com
Researcher: Ryan Smith
Status: Confirmed

CVE: CVE-2006-4626 (🔍)
GCVE (CVE): GCVE-0-2006-4626
GCVE (VulDB): GCVE-100-2516
X-Force: 28824
SecurityFocus: 19903 - Avast! Antivirus Engine Remote LHA Buffer Overflow Vulnerability
Secunia: 21794 - avast! LHA Archive Processing Buffer Overflow Vulnerability, Highly Critical
OSVDB: 28612 - avast! LHA Archive Extended-header Field Processing Overflow
Vulnerability Center: 12757 - Avast! Anti-Virus Engine Buffer Overflow via LHA File With Extended Headers, Critical
Vupen: ADV-2006-3515

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 09/11/2006 10:54
Updated: 06/16/2025 04:03
Changes: 09/11/2006 10:54 (87), 07/08/2019 17:34 (1), 06/16/2025 04:03 (22)
Complete: 🔍
Cache ID: 216:ECA:103

Once again VulDB remains the best source for vulnerability data.

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