Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-1252
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 07:09 UTC · Revision 1
Source evidence
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.
osv:CVE-2021-1252
Complete source record
{
"id": "27e7ae0b11608f39a0d5cea95f49240b66f22aa76c85bf0aeb58678e42898c6d",
"url": "https://osv.dev/vulnerability/CVE-2021-1252",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-1252",
"summary": "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.",
"evidence": "osv:CVE-2021-1252",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2021-1252",
"aliases": [
"CVE-2021-1252"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/cisco-talos/clamav",
"type": "GIT",
"events": [
{
"introduced": "31824a659dff37ae03e3419395bb68e659c2b165"
},
{
"last_affected": "e7f5f53737f51f3b8395c12b1f804dc6c2181169"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:clamav:clamav:0.103.0:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0.103.0"
},
{
"last_affected": "0.103.0"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:clamav:clamav:0.103.1:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0.103.1"
},
{
"last_affected": "0.103.1"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"0.103.0",
"0.103.1",
"clamav-0.103.1",
"clamav-0.103.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-1252.json"
}
}
],
"modified": "2026-10-24T10:30:49.499034650Z",
"provider": "osv",
"references": [
"https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2021-1252",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 437007,
"published_at": "2021-04-08T05:15:12.237+00:00"
}