Multiple format string vulnerabilities in the logging code in Clam AntiVirus (ClamAV) before 0.88.1 might allow remote attackers to execute arbitrary code. NOTE: as of 20060410, it is unclear whether this is a vulnerability, as there is some evidence that the arguments are actually being sanitized properly.

Stack-based buffer overflow in the cliurlcanon function in libclamav/phishcheck.c in ClamAV before 0.95.1 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a crafted URL.

ClamAV before 0.96 does not properly handle the (1) CAB and (2) 7z file formats, which allows remote attackers to bypass virus detection via a crafted archive that is compatible with standard archive utilities.

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms in the message parsing function on an affected system. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted email to the affected device. This action could cause a messageAddArgument (in message.c) buffer overflow condition when ClamAV scans the malicious email, allowing the attacker to potentially cause a DoS condition or execute arbitrary code on an affected device.

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms in mew packet files sent to an affected device. A successful exploit could cause a heap-based buffer over-read condition in mew.c when ClamAV scans the malicious file, allowing the attacker to cause a DoS condition or potentially execute arbitrary code on the affected device.

Multiple unspecified vulnerabilities in ClamAV before 0.94 have unknown impact and attack vectors related to file descriptor leaks on the "error path" in (1) libclamav/others.c and (2) libclamav/sis.c.

The unmew11 function in libclamav/mew.c in libclamav in ClamAV before 0.92.1 has unknown impact and attack vectors that trigger "heap corruption."

A vulnerability in the PDF scanning processes of ClamAV could allow an unauthenticated, remote attacker to cause a buffer overflow condition, cause a denial of service (DoS) condition, or execute arbitrary code on an affected device. This vulnerability exists because memory buffers are allocated incorrectly when PDF files are processed. An attacker could exploit this vulnerability by submitting a crafted PDF file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to trigger a buffer overflow, likely resulting in the termination of the ClamAV scanning process and a DoS condition on the affected software. Although unproven, there is also a possibility that an attacker could leverage the buffer overflow to execute arbitrary code with the privileges of the ClamAV process.

On Feb 15, 2023, the following vulnerability in the ClamAV scanning library was disclosed: A vulnerability in the HFS+ partition file parser of ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier could allow an unauthenticated, remote attacker to execute arbitrary code. This vulnerability is due to a missing buffer size check that may result in a heap buffer overflow write. An attacker could exploit this vulnerability by submitting a crafted HFS+ partition file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to execute arbitrary code with the privileges of the ClamAV scanning process, or else crash the process, resulting in a denial of service (DoS) condition. For a description of this vulnerability, see the ClamAV blog ["https://blog.clamav.net/"].

There is a possible heap overflow in libclamav/fsg.c before 0.100.0.

ClamAV before 0.97.7 has buffer overflow in the libclamav component

ClamAV before 0.97.7 has WWPack corrupt heap memory

clamav 0.91.2 suffers from a floating point exception when using ScanOLE2.

A vulnerability in the RAR file scanning functionality of Clam AntiVirus (ClamAV) Software versions 0.101.1 and 0.101.0 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to a lack of proper error-handling mechanisms when processing nested RAR files sent to an affected device. An attacker could exploit this vulnerability by sending a crafted RAR file to an affected device. An exploit could allow the attacker to view or create arbitrary files on the targeted system.

Buffer overflow in the findstreambounds function in pdf.c in libclamav in ClamAV before 0.96.3 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted PDF document. NOTE: some of these details are obtained from third party information.

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms when handling Portable Document Format (.pdf) files sent to an affected device. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted .pdf file to an affected device. This action could cause a handlepdfname (in pdf.c) buffer overflow when ClamAV scans the malicious file, allowing the attacker to cause a DoS condition or potentially execute arbitrary code.

ClamAV 0.94.1 and possibly 0.93.1, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.

ClamAV versions prior to 0.103.0-rc contain a vulnerability in function name processing through the ClamBC bytecode interpreter that allows attackers to manipulate bytecode function names. Attackers can exploit the weak input validation in function name encoding to potentially execute malicious bytecode or cause unexpected behavior in the ClamAV engine.

A vulnerability in the OLE2 file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device.The vulnerability is due to incorrect use of the realloc function that may result in a double-free. An attacker could exploit this vulnerability by submitting a crafted OLE2 file to be scanned by ClamAV on the affected device. An exploit could allow the attacker to cause the ClamAV scanning process to crash, resulting in a denial of service condition.

On April 20, 2022, the following vulnerability in the ClamAV scanning library versions 0.103.5 and earlier and 0.104.2 and earlier was disclosed: A vulnerability in CHM file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. For a description of this vulnerability, see the ClamAV blog. This advisory will be updated as additional information becomes available.

On May 4, 2022, the following vulnerability in the ClamAV scanning library versions 0.103.5 and earlier and 0.104.2 and earlier was disclosed: A vulnerability in CHM file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. For a description of this vulnerability, see the ClamAV blog. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-dos-prVGcHLd

On April 20, 2022, the following vulnerability in the ClamAV scanning library versions 0.103.5 and earlier and 0.104.2 and earlier was disclosed: A vulnerability in the TIFF file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. For a description of this vulnerability, see the ClamAV blog. This advisory will be updated as additional information becomes available.

On April 20, 2022, the following vulnerability in the ClamAV scanning library versions 0.103.5 and earlier and 0.104.2 and earlier was disclosed: A vulnerability in HTML file parser of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. For a description of this vulnerability, see the ClamAV blog. This advisory will be updated as additional information becomes available.

A vulnerability in the regex module used by the signature database load module of Clam AntiVirus (ClamAV) versions 0.104.0 through 0.104.2 and LTS version 0.103.5 and prior versions could allow an authenticated, local attacker to crash ClamAV at database load time, and possibly gain code execution. The vulnerability is due to improper bounds checking that may result in a multi-byte heap buffer overwflow write. An attacker could exploit this vulnerability by placing a crafted CDB ClamAV signature database file in the ClamAV database directory. An exploit could allow the attacker to run code as the clamav user.

libclamav/untar.c in ClamAV before 0.95 allows remote attackers to cause a denial of service (infinite loop) via a crafted TAR file that causes (1) clamd and (2) clamscan to hang.

mspack/lzxd.c in libmspack 0.5alpha, as used in ClamAV 0.99.2, allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted CHM file.

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper input validation checking mechanisms in mbox.c during certain mail parsing functions of the ClamAV software. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted email to the affected device. An exploit could trigger a NULL pointer dereference condition when ClamAV scans the malicious email, which may result in a DoS condition.

Last updated 25 August 2025

Last updated 25 August 2025

A vulnerability in the Excel XLM macro parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper error handling that may result in an infinite loop. An attacker could exploit this vulnerability by sending a crafted Excel file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process hang, resulting in a denial of service condition.