LowFix available
libslirp, qemu — security advisory
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the bootp_input() function and could occur while processing a udp packet that is smaller than the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of uninitialized heap memory from the host. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.
- Products
- libslirp, qemu
- Affected versions
- Not specified
- Fixed versions
- 1:4.1-2, 4.6.1-1
- CVEs
- CVE-2021-3592
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:35 UTC · Revision 1
Source evidence
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the bootp_input() function and could occur while processing a udp packet that is smaller than the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of uninitialized heap memory from the host. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.
osv:DEBIAN-CVE-2021-3592
libslirp
Fixed versions: 4.6.1-1
libslirp
Fixed versions: 4.6.1-1
libslirp
Fixed versions: 4.6.1-1
qemu
Fixed versions: 1:4.1-2
qemu
Fixed versions: 1:4.1-2
qemu
Fixed versions: 1:4.1-2
Complete source record
{
"id": "06925f7f03560c86f4772a765f26f3de7199718064e55619eec4ca77150b07a4",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-3592",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-3592",
"summary": "An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the bootp_input() function and could occur while processing a udp packet that is smaller than the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of uninitialized heap memory from the host. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.",
"evidence": "osv:DEBIAN-CVE-2021-3592",
"products": [
{
"name": {
"value": "libslirp",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.6.1-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
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},
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},
{
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{
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{
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"affected_versions": []
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],
"severity": "low",
"structured": {
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"aliases": [
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"metrics": [
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"affected": [
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"events": [
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"package": {
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"ecosystem": "Debian:12"
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{
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"ecosystem": "Debian:13"
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},
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},
{
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],
"package": {
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"ecosystem": "Debian:13"
},
"database_specific": {
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},
"ecosystem_specific": {
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},
{
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"package": {
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},
"database_specific": {
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},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:27.561643993Z",
"provider": "osv",
"upstream": [
"CVE-2021-3592"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-3592"
]
},
"related_cves": [
{
"value": "CVE-2021-3592",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 421573,
"published_at": "2021-06-15T21:15:09.307+00:00"
}