CVE-2021-47496 (GCVE-0-2021-47496)
Vulnerability from cvelistv5 – Published: 2024-05-22 08:19 – Updated: 2026-08-05 08:48
VLAI
EPSS
VEX
Title
net/tls: Fix flipped sign in tls_err_abort() calls
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/tls: Fix flipped sign in tls_err_abort() calls
sk->sk_err appears to expect a positive value, a convention that ktls
doesn't always follow and that leads to memory corruption in other code.
For instance,
[kworker]
tls_encrypt_done(..., err=<negative error from crypto request>)
tls_err_abort(.., err)
sk->sk_err = err;
[task]
splice_from_pipe_feed
...
tls_sw_do_sendpage
if (sk->sk_err) {
ret = -sk->sk_err; // ret is positive
splice_from_pipe_feed (continued)
ret = actor(...) // ret is still positive and interpreted as bytes
// written, resulting in underflow of buf->len and
// sd->len, leading to huge buf->offset and bogus
// addresses computed in later calls to actor()
Fix all tls_err_abort() callers to pass a negative error code
consistently and centralize the error-prone sign flip there, throwing in
a warning to catch future misuse and uninlining the function so it
really does only warn once.
Severity
9.8 (Critical)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-09-10 15:35 UTC
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < e0cfd5159f314d6b304d030363650b06a2299cbb
(git)
Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < f3dec7e7ace38224f82cf83f0049159d067c2e19 (git) Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < e41473543f75f7dbc5d605007e6f883f1bd13b9a (git) Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < da353fac65fede6b8b4cfe207f0d9408e3121105 (git) |
guessed | |
| Linux | Linux |
Affected:
4.17
Unaffected: 0 , < 4.17 (semver) Unaffected: 5.4.157 , ≤ 5.4.* (semver) Unaffected: 5.10.77 , ≤ 5.10.* (semver) Unaffected: 5.14.16 , ≤ 5.14.* (semver) Unaffected: 5.15 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-04T05:39:59.752Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2021-47496",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T15:35:52.280096Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2024-09-11T17:33:23.659Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "e0cfd5159f314d6b304d030363650b06a2299cbb",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "f3dec7e7ace38224f82cf83f0049159d067c2e19",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "e41473543f75f7dbc5d605007e6f883f1bd13b9a",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "da353fac65fede6b8b4cfe207f0d9408e3121105",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"lessThan": "4.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.77",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.14.*",
"status": "unaffected",
"version": "5.14.16",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "5.15",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.4.157",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.77",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.14.16",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15",
"versionStartIncluding": "4.17",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix flipped sign in tls_err_abort() calls\n\nsk-\u003esk_err appears to expect a positive value, a convention that ktls\ndoesn\u0027t always follow and that leads to memory corruption in other code.\nFor instance,\n\n [kworker]\n tls_encrypt_done(..., err=\u003cnegative error from crypto request\u003e)\n tls_err_abort(.., err)\n sk-\u003esk_err = err;\n\n [task]\n splice_from_pipe_feed\n ...\n tls_sw_do_sendpage\n if (sk-\u003esk_err) {\n ret = -sk-\u003esk_err; // ret is positive\n\n splice_from_pipe_feed (continued)\n ret = actor(...) // ret is still positive and interpreted as bytes\n // written, resulting in underflow of buf-\u003elen and\n // sd-\u003elen, leading to huge buf-\u003eoffset and bogus\n // addresses computed in later calls to actor()\n\nFix all tls_err_abort() callers to pass a negative error code\nconsistently and centralize the error-prone sign flip there, throwing in\na warning to catch future misuse and uninlining the function so it\nreally does only warn once."
}
],
"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 bug is in kTLS (net/tls): a remote peer of a kTLS-offloaded service can set a negative sk_err via tls_read_size()/tls_decrypt_done() by sending a malformed TLS record, then the server\u2019s ordinary sendfile/splice TX path (tls_sw_do_sendpage) mis-handles that sk_err; per guidance, kTLS bugs driven by remote peer data are Network.\nAC:L - The attacker fully controls the malformed TLS records and can send them while the server is mid-sendfile/splice (or retry across connections); no race or memory-layout condition outside attacker influence is required for the sign-flip corruption.\nPR:N - An unauthenticated client of a public kTLS HTTPS/TLS service needs no account or capability on the host; setsockopt(TCP_ULP,\"tls\")/TLS_TX|RX also requires no capability once the tls module is loaded.\nUI:N - Exploitation needs only the attacker\u2019s TLS traffic plus the server\u2019s normal sendfile/splice response path; no separate victim user or administrator action is required.\nS:U - The pipe-buffer underflow and resulting UAF/OOB access corrupt kernel memory within the same host kernel authority and do not cross a VM, IOMMU, or sandbox boundary.\nC:H - splice_from_pipe_feed underflows buf-\u003elen and advances buf-\u003eoffset into bogus addresses, and syzbot observed a KASAN use-after-free read in __crypto_xor; that memory-corruption/UAF primitive is leverageable for arbitrary kernel disclosure.\nI:H - The same underflow drives later actor()/sendpage calls with huge offsets into reclaimed or adjacent memory, yielding OOB write and UAF write primitives that can be escalated to control-flow hijack.\nA:H - The resulting use-after-free and out-of-bounds accesses reliably oops/panic the kernel (as in the syzbot KASAN report), fully disrupting availability."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T08:48:05.957Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
},
{
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
}
],
"title": "net/tls: Fix flipped sign in tls_err_abort() calls",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2021-47496",
"datePublished": "2024-05-22T08:19:43.489Z",
"dateReserved": "2024-05-22T06:20:56.202Z",
"dateUpdated": "2026-08-05T08:48:05.957Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-47496",
"date": "2026-11-09",
"epss": "0.00483",
"percentile": "0.4195"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "e0cfd5159f314d6b304d030363650b06a2299cbb",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "f3dec7e7ace38224f82cf83f0049159d067c2e19",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "e41473543f75f7dbc5d605007e6f883f1bd13b9a",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "da353fac65fede6b8b4cfe207f0d9408e3121105",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"lessThan": "4.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.77",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.14.*",
"status": "unaffected",
"version": "5.14.16",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "5.15",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "965296D4-AA37-4DB2-9ED7-71310E9A6C11",
"versionEndExcluding": "5.4.157",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "26EB7ED9-AEA3-4829-8B5E-08571262F72A",
"versionEndExcluding": "5.10.77",
"versionStartIncluding": "5.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2681B950-4548-4649-A9E1-4124B59FC09C",
"versionEndExcluding": "5.14.16",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*",
"matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*",
"matchCriteriaId": "60134C3A-06E4-48C1-B04F-2903732A4E56",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*",
"matchCriteriaId": "0460DA88-8FE1-46A2-9DDA-1F1ABA552E71",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*",
"matchCriteriaId": "AF55383D-4DF2-45DC-93F7-571F4F978EAB",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*",
"matchCriteriaId": "9E9481B2-8AA6-4CBD-B5D3-C10F51FF6D01",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*",
"matchCriteriaId": "EBD45831-4B79-42BC-ABC0-86870F0DEA89",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:*",
"matchCriteriaId": "948A6B8D-1B72-4945-8680-354E53BE1C80",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix flipped sign in tls_err_abort() calls\n\nsk-\u003esk_err appears to expect a positive value, a convention that ktls\ndoesn\u0027t always follow and that leads to memory corruption in other code.\nFor instance,\n\n [kworker]\n tls_encrypt_done(..., err=\u003cnegative error from crypto request\u003e)\n tls_err_abort(.., err)\n sk-\u003esk_err = err;\n\n [task]\n splice_from_pipe_feed\n ...\n tls_sw_do_sendpage\n if (sk-\u003esk_err) {\n ret = -sk-\u003esk_err; // ret is positive\n\n splice_from_pipe_feed (continued)\n ret = actor(...) // ret is still positive and interpreted as bytes\n // written, resulting in underflow of buf-\u003elen and\n // sd-\u003elen, leading to huge buf-\u003eoffset and bogus\n // addresses computed in later calls to actor()\n\nFix all tls_err_abort() callers to pass a negative error code\nconsistently and centralize the error-prone sign flip there, throwing in\na warning to catch future misuse and uninlining the function so it\nreally does only warn once."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/tls: corrige las llamadas invertidas de tls_err_abort() sk-\u0026gt;sk_err parece esperar un valor positivo, una convenci\u00f3n que ktls no siempre sigue y que conduce a da\u00f1os en la memoria en otro c\u00f3digo. Por ejemplo, [kworker] tls_encrypt_done(..., err=) tls_err_abort(.., err) sk-\u0026gt;sk_err = err; [tarea] splice_from_pipe_feed ... tls_sw_do_sendpage if (sk-\u0026gt;sk_err) { ret = -sk-\u0026gt;sk_err; // ret es positivo splice_from_pipe_feed (continuaci\u00f3n) ret = actor(...) // ret sigue siendo positivo y se interpreta como bytes // escritos, lo que resulta en un desbordamiento insuficiente de buf-\u0026gt;len y // sd-\u0026gt;len, lo que genera enormes buf-\u0026gt;offset y bogus // direcciones calculadas en llamadas posteriores a actor(). Repare todas las llamadas tls_err_abort() para que pasen un c\u00f3digo de error negativo de manera consistente y centralice el cambio de se\u00f1al propenso a errores all\u00ed, lanzando una advertencia para detectar futuros usos indebidos y eliminaci\u00f3n de l\u00edneas. la funci\u00f3n por lo que realmente solo advierte una vez."
}
],
"id": "CVE-2021-47496",
"lastModified": "2026-08-04T10:17:05.910",
"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"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-47496",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T15:35:52.280096Z",
"version": "2.0.3"
}
}
]
},
"published": "2024-05-22T09:15:11.447",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-787"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-11-06T12:12:08+00:00",
"cve": "CVE-2021-47496",
"id": "CVE-2021-47496",
"initial_release_date": "2021-01-01T00:00:00+00:00",
"product_status:known_affected": "48",
"product_status:known_not_affected": "151",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: net/tls: Fix flipped sign in tls_err_abort() calls",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47496.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-04T05:39:59.752Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"tags": [
"x_transferred"
],
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2021-47496",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T15:35:52.280096Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2024-09-11T12:42:16.475Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "e0cfd5159f314d6b304d030363650b06a2299cbb",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "f3dec7e7ace38224f82cf83f0049159d067c2e19",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "e41473543f75f7dbc5d605007e6f883f1bd13b9a",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
},
{
"lessThan": "da353fac65fede6b8b4cfe207f0d9408e3121105",
"status": "affected",
"version": "c46234ebb4d1eee5e09819f49169e51cfc6eb909",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/net/tls.h",
"net/tls/tls_sw.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"lessThan": "4.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.77",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.14.*",
"status": "unaffected",
"version": "5.14.16",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "5.15",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.4.157",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.77",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.14.16",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15",
"versionStartIncluding": "4.17",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix flipped sign in tls_err_abort() calls\n\nsk-\u003esk_err appears to expect a positive value, a convention that ktls\ndoesn\u0027t always follow and that leads to memory corruption in other code.\nFor instance,\n\n [kworker]\n tls_encrypt_done(..., err=\u003cnegative error from crypto request\u003e)\n tls_err_abort(.., err)\n sk-\u003esk_err = err;\n\n [task]\n splice_from_pipe_feed\n ...\n tls_sw_do_sendpage\n if (sk-\u003esk_err) {\n ret = -sk-\u003esk_err; // ret is positive\n\n splice_from_pipe_feed (continued)\n ret = actor(...) // ret is still positive and interpreted as bytes\n // written, resulting in underflow of buf-\u003elen and\n // sd-\u003elen, leading to huge buf-\u003eoffset and bogus\n // addresses computed in later calls to actor()\n\nFix all tls_err_abort() callers to pass a negative error code\nconsistently and centralize the error-prone sign flip there, throwing in\na warning to catch future misuse and uninlining the function so it\nreally does only warn once."
}
],
"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 bug is in kTLS (net/tls): a remote peer of a kTLS-offloaded service can set a negative sk_err via tls_read_size()/tls_decrypt_done() by sending a malformed TLS record, then the server\u2019s ordinary sendfile/splice TX path (tls_sw_do_sendpage) mis-handles that sk_err; per guidance, kTLS bugs driven by remote peer data are Network.\nAC:L - The attacker fully controls the malformed TLS records and can send them while the server is mid-sendfile/splice (or retry across connections); no race or memory-layout condition outside attacker influence is required for the sign-flip corruption.\nPR:N - An unauthenticated client of a public kTLS HTTPS/TLS service needs no account or capability on the host; setsockopt(TCP_ULP,\"tls\")/TLS_TX|RX also requires no capability once the tls module is loaded.\nUI:N - Exploitation needs only the attacker\u2019s TLS traffic plus the server\u2019s normal sendfile/splice response path; no separate victim user or administrator action is required.\nS:U - The pipe-buffer underflow and resulting UAF/OOB access corrupt kernel memory within the same host kernel authority and do not cross a VM, IOMMU, or sandbox boundary.\nC:H - splice_from_pipe_feed underflows buf-\u003elen and advances buf-\u003eoffset into bogus addresses, and syzbot observed a KASAN use-after-free read in __crypto_xor; that memory-corruption/UAF primitive is leverageable for arbitrary kernel disclosure.\nI:H - The same underflow drives later actor()/sendpage calls with huge offsets into reclaimed or adjacent memory, yielding OOB write and UAF write primitives that can be escalated to control-flow hijack.\nA:H - The resulting use-after-free and out-of-bounds accesses reliably oops/panic the kernel (as in the syzbot KASAN report), fully disrupting availability."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T08:48:05.957Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb"
},
{
"url": "https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19"
},
{
"url": "https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a"
},
{
"url": "https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"
}
],
"title": "net/tls: Fix flipped sign in tls_err_abort() calls",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2021-47496",
"datePublished": "2024-05-22T08:19:43.489Z",
"dateReserved": "2024-05-22T06:20:56.202Z",
"dateUpdated": "2026-08-05T08:48:05.957Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
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.