{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21756", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.760Z", "datePublished": "2025-02-27T02:18:11.547Z", "dateUpdated": "2026-08-05T11:54:09.890Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:09.890Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: Keep the binding until socket destruction\n\nPreserve sockets bindings; this includes both resulting from an explicit\nbind() and those implicitly bound through autobind during connect().\n\nPrevents socket unbinding during a transport reassignment, which fixes a\nuse-after-free:\n\n 1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2)\n 2. transport->release() calls vsock_remove_bound() without checking if\n sk was bound and moved to bound list (refcnt=1)\n 3. vsock_bind() assumes sk is in unbound list and before\n __vsock_insert_bound(vsock_bound_sockets()) calls\n __vsock_remove_bound() which does:\n list_del_init(&vsk->bound_table); // nop\n sock_put(&vsk->sk); // refcnt=0\n\nBUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730\nRead of size 4 at addr ffff88816b46a74c by task a.out/2057\n dump_stack_lvl+0x68/0x90\n print_report+0x174/0x4f6\n kasan_report+0xb9/0x190\n __vsock_bind+0x62e/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nAllocated by task 2057:\n kasan_save_stack+0x1e/0x40\n kasan_save_track+0x10/0x30\n __kasan_slab_alloc+0x85/0x90\n kmem_cache_alloc_noprof+0x131/0x450\n sk_prot_alloc+0x5b/0x220\n sk_alloc+0x2c/0x870\n __vsock_create.constprop.0+0x2e/0xb60\n vsock_create+0xe4/0x420\n __sock_create+0x241/0x650\n __sys_socket+0xf2/0x1a0\n __x64_sys_socket+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nFreed by task 2057:\n kasan_save_stack+0x1e/0x40\n kasan_save_track+0x10/0x30\n kasan_save_free_info+0x37/0x60\n __kasan_slab_free+0x4b/0x70\n kmem_cache_free+0x1a1/0x590\n __sk_destruct+0x388/0x5a0\n __vsock_bind+0x5e1/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150\nRIP: 0010:refcount_warn_saturate+0xce/0x150\n __vsock_bind+0x66d/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nrefcount_t: underflow; use-after-free.\nWARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150\nRIP: 0010:refcount_warn_saturate+0xee/0x150\n vsock_remove_bound+0x187/0x1e0\n __vsock_release+0x383/0x4a0\n vsock_release+0x90/0x120\n __sock_release+0xa3/0x250\n sock_close+0x14/0x20\n __fput+0x359/0xa80\n task_work_run+0x107/0x1d0\n do_exit+0x847/0x2560\n do_group_exit+0xb8/0x250\n __x64_sys_exit_group+0x3a/0x50\n x64_sys_call+0xfec/0x14f0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "Deterministic UAF in vsock socket binding during transport reassignment. connect() unbinds the socket dropping refcount, then bind() triggers use-after-free exploitable for privilege escalation." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/vmw_vsock/af_vsock.c" ], "versions": [ { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "e7754d564579a5db9c5c9f74228df5d6dd6f1173", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "e48fcb403c2d0e574c19683f09399ab4cf67809c", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "42b33381e5e1f2b967dc4fb4221ddb9aaf10d197", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "3f43540166128951cc1be7ab1ce6b7f05c670d8b", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "645ce25aa0e67895b11d89f27bb86c9d444c40f8", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "b1afd40321f1c243cffbcf40ea7ca41aca87fa5e", "status": "affected", "versionType": "git" }, { "version": "c0cfa2d8a788fcf45df5bf4070ab2474c88d543a", "lessThan": "fcdd2242c0231032fc84e1404315c245ae56322a", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/vmw_vsock/af_vsock.c" ], "versions": [ { "version": "5.5", "status": "affected" }, { "version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.131", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.79", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.16", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.4", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.1.131" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.6.79" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.12.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e7754d564579a5db9c5c9f74228df5d6dd6f1173" }, { "url": "https://git.kernel.org/stable/c/e48fcb403c2d0e574c19683f09399ab4cf67809c" }, { "url": "https://git.kernel.org/stable/c/42b33381e5e1f2b967dc4fb4221ddb9aaf10d197" }, { "url": "https://git.kernel.org/stable/c/3f43540166128951cc1be7ab1ce6b7f05c670d8b" }, { "url": "https://git.kernel.org/stable/c/645ce25aa0e67895b11d89f27bb86c9d444c40f8" }, { "url": "https://git.kernel.org/stable/c/b1afd40321f1c243cffbcf40ea7ca41aca87fa5e" }, { "url": "https://git.kernel.org/stable/c/fcdd2242c0231032fc84e1404315c245ae56322a" } ], "title": "vsock: Keep the binding until socket destruction", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "problemTypes": [ { "descriptions": [ { "type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free" } ] } ], "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "timestamp": "2025-08-14T21:01:56.187542Z", "id": "CVE-2025-21756", "options": [ { "Exploitation": "poc" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-08-14T21:02:02.327Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:37:01.186Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:39:57.826Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" } ] } ] } }