CVE-2022-49264

{"id": "CVE-2022-49264", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-02-26T07:01:03.337", "references": [{"url": "https://git.kernel.org/stable/c/1290eb4412aa0f0e9f3434b406dc8e255da85f9e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/1fe82bfd9e4ce93399d815ca458b58505191c3e8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/27a6f495b63a1804cc71be45911065db7757a98c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/41f6ea5b9aaa28b740d47ffe995a5013211fdbb0", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/98e0c7c702894987732776736c99b85ade6fba45", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a8054d3fa5deb84b215d6be1b910a978f3cb840d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b50fb8dbc8b81aaa126387de428f4c42a7c72a73", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cfbfff8ce5e3d674947581f1eb9af0a1b1807950", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dcd46d897adb70d63e025f175a00a89797d31a43", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nexec: Force single empty string when argv is empty\n\nQuoting[1] Ariadne Conill:\n\n\"In several other operating systems, it is a hard requirement that the\nsecond argument to execve(2) be the name of a program, thus prohibiting\na scenario where argc < 1. POSIX 2017 also recommends this behaviour,\nbut it is not an explicit requirement[2]:\n\n The argument arg0 should point to a filename string that is\n associated with the process being started by one of the exec\n functions.\n...\nInterestingly, Michael Kerrisk opened an issue about this in 2008[3],\nbut there was no consensus to support fixing this issue then.\nHopefully now that CVE-2021-4034 shows practical exploitative use[4]\nof this bug in a shellcode, we can reconsider.\n\nThis issue is being tracked in the KSPP issue tracker[5].\"\n\nWhile the initial code searches[6][7] turned up what appeared to be\nmostly corner case tests, trying to that just reject argv == NULL\n(or an immediately terminated pointer list) quickly started tripping[8]\nexisting userspace programs.\n\nThe next best approach is forcing a single empty string into argv and\nadjusting argc to match. The number of programs depending on argc == 0\nseems a smaller set than those calling execve with a NULL argv.\n\nAccount for the additional stack space in bprm_stack_limits(). Inject an\nempty string when argc == 0 (and set argc = 1). Warn about the case so\nuserspace has some notice about the change:\n\n process './argc0' launched './argc0' with NULL argv: empty string added\n\nAdditionally WARN() and reject NULL argv usage for kernel threads.\n\n[1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org/\n[2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html\n[3] https://bugzilla.kernel.org/show_bug.cgi?id=8408\n[4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt\n[5] https://github.com/KSPP/linux/issues/176\n[6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&literal=0\n[7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%2C%5Cs*NULL&literal=0\n[8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: exec: Forzar una sola cadena vac\u00eda cuando argv est\u00e1 vac\u00edo Citando[1] a Ariadne Conill: \"En varios otros sistemas operativos, es un requisito estricto que el segundo argumento de execve(2) sea el nombre de un programa, lo que proh\u00edbe un escenario donde argc &lt; 1. POSIX 2017 tambi\u00e9n recomienda este comportamiento, pero no es un requisito expl\u00edcito[2]: el argumento arg0 debe apuntar a una cadena de nombre de archivo que est\u00e9 asociada con el proceso que inicia una de las funciones exec. ... Curiosamente, Michael Kerrisk abri\u00f3 un problema sobre esto en 2008[3], pero no hubo consenso para apoyar la soluci\u00f3n de este problema en ese momento. Con suerte, ahora que CVE-2021-4034 muestra un uso explotador pr\u00e1ctico[4] de este error en un shellcode, podemos reconsiderarlo. Este problema se est\u00e1 rastreando en el rastreador de problemas de KSPP[5]\". Si bien las b\u00fasquedas de c\u00f3digo iniciales[6][7] dieron como resultado lo que parec\u00edan ser principalmente pruebas de casos extremos, intentar simplemente rechazar argv == NULL (o una lista de punteros terminada inmediatamente) r\u00e1pidamente comenz\u00f3 a hacer tropezar[8] a los programas de espacio de usuario existentes. El siguiente mejor enfoque es forzar una sola cadena vac\u00eda en argv y ajustar argc para que coincida. La cantidad de programas que dependen de argc == 0 parece un conjunto m\u00e1s peque\u00f1o que los que llaman a execve con un argv NULL. Tenga en cuenta el espacio de pila adicional en bprm_stack_limits(). Inyecte una cadena vac\u00eda cuando argc == 0 (y establezca argc = 1). Advertir sobre el caso para que el espacio de usuario tenga alg\u00fan aviso sobre el cambio: proceso './argc0' lanzado './argc0' con argv NULL: cadena vac\u00eda agregada Adem\u00e1s, WARN() y rechace el uso de argv NULL para subprocesos del kernel. [1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org/ [2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html [3] https://bugzilla.kernel.org/show_bug.cgi?id=8408 [4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt [5] https://github.com/KSPP/linux/issues/176 [6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&amp;literal=0 [7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%2C%5Cs*NULL&amp;literal=0 [8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/"}], "lastModified": "2025-10-21T11:50:45.753", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "84DC7D23-B08E-4885-9766-0483E535A1D2", "versionEndExcluding": "4.9.317"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "39AF7F30-D3BB-4981-9D6A-6ECAD2A598AF", "versionEndExcluding": "4.14.282", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FEDF30DC-BB12-4C4C-A134-AA5D59D73C0C", "versionEndExcluding": "4.19.246", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F7FDD830-741D-44F7-A537-13755A4314DE", "versionEndExcluding": "5.4.197", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "91D3BFD0-D3F3-4018-957C-96CCBF357D79", "versionEndExcluding": "5.10.110", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "27C42AE8-B387-43E2-938A-E1C8B40BE6D5", "versionEndExcluding": "5.15.33", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "20C43679-0439-405A-B97F-685BEE50613B", "versionEndExcluding": "5.16.19", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "210C679C-CF84-44A3-8939-E629C87E54BF", "versionEndExcluding": "5.17.2", "versionStartIncluding": "5.17"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}