High
isync — security advisory
A flaw was found in mbsync before v1.3.6 and v1.4.2, where an unchecked pointer cast allows a malicious or compromised server to write an arbitrary integer value past the end of a heap-allocated structure by issuing an unexpected APPENDUID response. This could be plausibly exploited for remote code execution on the client.
- Products
- isync
- Affected versions
- 1.1.2-1, 1.2.1-2, 1.3.0-1, 1.3.0-1build1, 1.3.0-1ubuntu0.18.04.0, 1.3.0-2, 1.3.0-2.2, 1.4.3-1, 1.4.4-1, 1.4.4-3, 1.4.4-3ubuntu0.22.04.1, 1.4.4-5, 1.4.4-5build2, 1.4.4-5build3, 1.5.1-1ubuntu1, 1.5.1-1ubuntu2, 1.5.1-1ubuntu4
- Fixed versions
- Not specified
- CVEs
- CVE-2021-3578
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:37 UTC · Revision 1
Source evidence
A flaw was found in mbsync before v1.3.6 and v1.4.2, where an unchecked pointer cast allows a malicious or compromised server to write an arbitrary integer value past the end of a heap-allocated structure by issuing an unexpected APPENDUID response. This could be plausibly exploited for remote code execution on the client.
osv:UBUNTU-CVE-2021-3578
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
isync
Fixed versions: Not specified
Complete source record
{
"id": "d74a4d1fe804a9a4a3b6c39e357859decf0c68bfb8846c8ce61d6030616f771b",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-3578",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2021-3578",
"summary": "A flaw was found in mbsync before v1.3.6 and v1.4.2, where an unchecked pointer cast allows a malicious or compromised server to write an arbitrary integer value past the end of a heap-allocated structure by issuing an unexpected APPENDUID response. This could be plausibly exploited for remote code execution on the client.",
"evidence": "osv:UBUNTU-CVE-2021-3578",
"products": [
{
"name": {
"value": "isync",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "1.1.2-1",
"evidence": "/affected/0/versions"
}
]
},
{
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"evidence": "/affected/1/package/name"
},
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},
{
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"evidence": "/affected/1/versions"
},
{
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{
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{
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{
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"evidence": "/affected/3/versions"
},
{
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"evidence": "/affected/3/versions"
},
{
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},
{
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{
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{
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},
{
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"evidence": "/affected/4/versions"
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},
{
"name": {
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},
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"affected_versions": [
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"evidence": "/affected/5/versions"
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{
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"evidence": "/affected/5/versions"
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},
{
"name": {
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"evidence": "/affected/6/package/name"
},
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"affected_versions": [
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"evidence": "/affected/6/versions"
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{
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"evidence": "/affected/6/versions"
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},
{
"name": {
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},
"prerequisites": [],
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"affected_versions": [
{
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"evidence": "/affected/7/versions"
},
{
"value": "1.5.1-1ubuntu2",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2021-3578",
"aliases": [
"UBUNTU-CVE-2021-3578"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
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"events": [
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"package": {
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},
"versions": [
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],
"database_specific": {
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},
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},
{
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"package": {
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"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
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"1.3.0-1",
"1.3.0-1build1",
"1.3.0-1ubuntu0.18.04.0"
],
"database_specific": {
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},
"ecosystem_specific": {
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{
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"package": {
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"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
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],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3578.json"
},
"ecosystem_specific": {
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"1.4.4-1",
"1.4.4-3",
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],
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"ecosystem_specific": {
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},
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],
"modified": "2026-10-17T12:57:13.740788340Z",
"provider": "osv",
"upstream": [
"CVE-2021-3578"
],
"references": [
"https://ubuntu.com/security/CVE-2021-3578",
"https://www.openwall.com/lists/oss-security/2021/06/07/1",
"https://www.cve.org/CVERecord?id=CVE-2021-3578"
]
},
"related_cves": [
{
"value": "CVE-2021-3578",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 356968,
"published_at": "2021-06-07T12:00:00+00:00"
}