FKIE_CVE-2021-4442
Vulnerability from fkie_nvd - Published: 2024-08-29 11:15 - Updated: 2026-06-17 04:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
tcp: add sanity tests to TCP_QUEUE_SEQ
Qingyu Li reported a syzkaller bug where the repro
changes RCV SEQ _after_ restoring data in the receive queue.
mprotect(0x4aa000, 12288, PROT_READ) = 0
mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer)
syslog shows:
[ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0
[ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0
This should not be allowed. TCP_QUEUE_SEQ should only be used
when queues are empty.
This patch fixes this case, and the tx path as well.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 5.12 | |
| linux | linux_kernel | 5.12 |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ipv4/tcp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "319f460237fc2965a80aa9a055044e1da7b3692a",
"status": "affected",
"version": "ee9952831cfd0bbe834f4a26489d7dce74582e37",
"versionType": "git"
},
{
"lessThan": "3bf899438c123c444f6b644a57784dfbb6b15ad6",
"status": "affected",
"version": "ee9952831cfd0bbe834f4a26489d7dce74582e37",
"versionType": "git"
},
{
"lessThan": "046f3c1c2ff450fb7ae53650e9a95e0074a61f3e",
"status": "affected",
"version": "ee9952831cfd0bbe834f4a26489d7dce74582e37",
"versionType": "git"
},
{
"lessThan": "3b72d5a703842f582502d97906f17d6ee122dac2",
"status": "affected",
"version": "ee9952831cfd0bbe834f4a26489d7dce74582e37",
"versionType": "git"
},
{
"lessThan": "8811f4a9836e31c14ecdf79d9f3cb7c5d463265d",
"status": "affected",
"version": "ee9952831cfd0bbe834f4a26489d7dce74582e37",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ipv4/tcp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.5"
},
{
"lessThan": "3.5",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"version": "4.19.181",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.106",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.24",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.11.*",
"status": "unaffected",
"version": "5.11.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "5.12",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "58EB7158-A900-4601-8CF0-D19F3929BBED",
"versionEndExcluding": "4.19.181",
"versionStartIncluding": "3.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2A66FDC0-50BA-4BCC-8BFE-2209436DDBF7",
"versionEndExcluding": "5.4.106",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "1E692548-C944-4984-9823-EE1EC83F4F2A",
"versionEndExcluding": "5.10.24",
"versionStartIncluding": "5.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "F83144BB-4FAB-40A1-8F52-8690FF516A33",
"versionEndExcluding": "5.11.7",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.12:rc1:*:*:*:*:*:*",
"matchCriteriaId": "07875739-0CCB-4F48-9330-3D4B6A4064FA",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.12:rc2:*:*:*:*:*:*",
"matchCriteriaId": "DA09B732-04F8-452C-94CF-97644E78684D",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: add sanity tests to TCP_QUEUE_SEQ\n\nQingyu Li reported a syzkaller bug where the repro\nchanges RCV SEQ _after_ restoring data in the receive queue.\n\nmprotect(0x4aa000, 12288, PROT_READ) = 0\nmmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000\nmmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000\nmmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000\nsocket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3\nsetsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0\nconnect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, \"::1\", \u0026sin6_addr), sin6_scope_id=0}, 28) = 0\nsetsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0\nsendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"0x0000000000000003\\0\\0\", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20\nsetsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0\nsetsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0\nrecvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer)\n\nsyslog shows:\n[ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0\n[ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0\n\nThis should not be allowed. TCP_QUEUE_SEQ should only be used\nwhen queues are empty.\n\nThis patch fixes this case, and the tx path as well."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tcp: agregar pruebas de cordura a TCP_QUEUE_SEQ Qingyu Li inform\u00f3 un error de syzkaller donde la reproducci\u00f3n cambia RCV SEQ _despu\u00e9s_ de restaurar datos en la cola de recepci\u00f3n. mprotect(0x4aa000, 12288, PROT_LECTURA) = 0 mmap(0x1ffff000, 4096, PROT_NINGUNO, MAPA_PRIVADO|MAPA_FIJO|MAPA_AN\u00d3NIMO, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_LECTURA|PROT_ESCRITURA|PROT_EJECUCI\u00d3N, MAPA_PRIVADO|MAPA_FIJO|MAPA_AN\u00d3NIMO, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NINGUNO, MAPA_PRIVADO|MAPA_FIJO|MAPA_AN\u00d3NIMO, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, \"::1\", \u0026amp;sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"0x0000000000000003\\0\\0\", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Conexi\u00f3n restablecida por el par) syslog muestra: [ 111.205099] TCP recvmsg seq # error 2: copiado 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] ADVERTENCIA: CPU: 1 PID: 356 en net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 Esto no deber\u00eda estar permitido. TCP_QUEUE_SEQ solo se debe utilizar cuando las colas est\u00e1n vac\u00edas. Este parche corrige este caso y tambi\u00e9n la ruta de transmisi\u00f3n."
}
],
"id": "CVE-2021-4442",
"lastModified": "2026-06-17T04:19:46.090",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-4442",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T15:27:19.469739Z",
"version": "2.0.3"
}
}
]
},
"published": "2024-08-29T11:15:23.413",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Exploit",
"Patch"
],
"url": "https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Exploit",
"Patch"
],
"url": "https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Exploit",
"Patch"
],
"url": "https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Exploit",
"Patch"
],
"url": "https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Exploit",
"Patch"
],
"url": "https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…