CVE-2023-53751 (GCVE-0-2023-53751)
Vulnerability from cvelistv5 – Published: 2025-12-08 01:19 – Updated: 2026-08-05 09:15
VLAI
EPSS
VEX
Title
cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname
Summary
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname
TCP_Server_Info::hostname may be updated once or many times during
reconnect, so protect its access outside reconnect path as well and
then prevent any potential use-after-free bugs.
Severity
9.8 (Critical)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 64d62ac6d6514cba1305bd08e271ec1843bdd612
(git)
Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < c511954bf142fe1995aec3c739a9f1a76990283a (git) Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 0b08c4c499200be67d54c439d56e5ea866869945 (git) Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 90c49fce1c43e1cc152695e20363ff5087897c09 (git) |
guessed | |
| Linux | Linux |
Affected:
5.0
Unaffected: 0 , < 5.0 (semver) Unaffected: 6.1.28 , ≤ 6.1.* (semver) Unaffected: 6.2.15 , ≤ 6.2.* (semver) Unaffected: 6.3.2 , ≤ 6.3.* (semver) Unaffected: 6.4 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/cifs/cifs_debug.c",
"fs/cifs/cifs_debug.h",
"fs/cifs/connect.c",
"fs/cifs/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "64d62ac6d6514cba1305bd08e271ec1843bdd612",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "c511954bf142fe1995aec3c739a9f1a76990283a",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "0b08c4c499200be67d54c439d56e5ea866869945",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "90c49fce1c43e1cc152695e20363ff5087897c09",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/cifs/cifs_debug.c",
"fs/cifs/cifs_debug.h",
"fs/cifs/connect.c",
"fs/cifs/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.0"
},
{
"lessThan": "5.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.28",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.2.*",
"status": "unaffected",
"version": "6.2.15",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.3.*",
"status": "unaffected",
"version": "6.3.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.4",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.28",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.2.15",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.3.2",
"versionStartIncluding": "5.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.4",
"versionStartIncluding": "5.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix potential use-after-free bugs in TCP_Server_Info::hostname\n\nTCP_Server_Info::hostname may be updated once or many times during\nreconnect, so protect its access outside reconnect path as well and\nthen prevent any potential use-after-free bugs."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - The vulnerability is in the CIFS/SMB client\u0027s handling of remote server data \u2014 the freed/reallocated `hostname` is derived from server-supplied DFS referral targets, and both the free side (forced reconnects) and the read side (error-path `cifs_server_dbg(VFS,...)` on malformed or bad-signature responses) are driven entirely by a remote SMB peer or an on-path network attacker.\nAC:L - The attacker controls both sides of the race: it can force unlimited reconnect cycles by dropping the TCP connection, chooses DFS target names so it controls the size and content of the freed/reallocated string for heap grooming, and can trigger the unlocked readers on demand via malformed responses, with unlimited retries.\nPR:N - No credentials or privileges on the target are required \u2014 the attacker is the remote SMB server or a network attacker, and the reader side is additionally reachable by any unprivileged local user through the world-readable (0444) /proc/fs/cifs/DebugData and 0644 /proc/fs/cifs/Stats.\nUI:N - Against a host with an already-established DFS CIFS mount (routine on enterprise servers and appliances), the attacker triggers reconnects and error paths on its own; no action by any user is needed at attack time.\nS:U - The use-after-free is in kernel memory and its impact stays within the kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `seq_printf(\"%s\", server-\u003ehostname)` on the dangling pointer copies freed heap memory into the world-readable /proc/fs/cifs/DebugData output, reading until an arbitrary NUL byte, giving an unbounded kernel heap disclosure whose contents the attacker can groom; the same data also leaks to dmesg via `cifs_server_dbg`.\nI:H - This is a use-after-free on an attacker-size-controlled slab object with a racing free/reassign of the same pointer, which enables heap spraying and reclaim of the freed slot; per kernel UAF scoring this is treated as exploitable for control-flow/memory corruption.\nA:H - Dereferencing the freed string over poisoned, unmapped, or reallocated memory produces a kernel oops/panic, and the attacker can repeat the reconnect-driven race indefinitely."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T09:15:47.928Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/64d62ac6d6514cba1305bd08e271ec1843bdd612"
},
{
"url": "https://git.kernel.org/stable/c/c511954bf142fe1995aec3c739a9f1a76990283a"
},
{
"url": "https://git.kernel.org/stable/c/0b08c4c499200be67d54c439d56e5ea866869945"
},
{
"url": "https://git.kernel.org/stable/c/90c49fce1c43e1cc152695e20363ff5087897c09"
}
],
"title": "cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2023-53751",
"datePublished": "2025-12-08T01:19:11.160Z",
"dateReserved": "2025-12-08T01:18:04.279Z",
"dateUpdated": "2026-08-05T09:15:47.928Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2023-53751",
"date": "2026-10-23",
"epss": "0.00415",
"percentile": "0.347"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/cifs/cifs_debug.c",
"fs/cifs/cifs_debug.h",
"fs/cifs/connect.c",
"fs/cifs/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "64d62ac6d6514cba1305bd08e271ec1843bdd612",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "c511954bf142fe1995aec3c739a9f1a76990283a",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "0b08c4c499200be67d54c439d56e5ea866869945",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
},
{
"lessThan": "90c49fce1c43e1cc152695e20363ff5087897c09",
"status": "affected",
"version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/cifs/cifs_debug.c",
"fs/cifs/cifs_debug.h",
"fs/cifs/connect.c",
"fs/cifs/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.0"
},
{
"lessThan": "5.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.28",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.2.*",
"status": "unaffected",
"version": "6.2.15",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.3.*",
"status": "unaffected",
"version": "6.3.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.4",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix potential use-after-free bugs in TCP_Server_Info::hostname\n\nTCP_Server_Info::hostname may be updated once or many times during\nreconnect, so protect its access outside reconnect path as well and\nthen prevent any potential use-after-free bugs."
}
],
"id": "CVE-2023-53751",
"lastModified": "2026-08-04T10:19:19.813",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2025-12-08T02:15:50.590",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0b08c4c499200be67d54c439d56e5ea866869945"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/64d62ac6d6514cba1305bd08e271ec1843bdd612"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/90c49fce1c43e1cc152695e20363ff5087897c09"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c511954bf142fe1995aec3c739a9f1a76990283a"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Deferred"
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-04T19:15:01+00:00",
"cve": "CVE-2023-53751",
"id": "CVE-2023-53751",
"initial_release_date": "2023-01-01T00:00:00+00:00",
"product_status:fixed": "1057",
"product_status:known_affected": "49",
"product_status:known_not_affected": "107",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: Linux kernel (CIFS): Use-after-free vulnerability allows data integrity compromise and denial of service",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53751.json",
"version": "3"
}
}
}
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