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CVE-2026-75900

Опубликовано: 19 авг. 2026
Источник: redhat
CVSS3: 6.1

Описание

An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.

Отчет

Red Hat rates this issue as Moderate impact. The SWTPM_NVRAM_CheckHeader() function in swtpm uses sizeof(bh) where bh is a pointer, checking buffer length against 8 bytes (on 64-bit) instead of the 10-byte packed blobheader struct. An attacker with access to the control channel can send an 8-byte state blob that passes this guard; the subsequent read of bh->totlen at offset 6 overreads the heap allocation by 2 bytes. The out-of-bounds value is then printed to the swtpm log, leaking a small amount of adjacent heap data. This is distinct from CVE-2022-23645, which added validation on the hdrsize field below this guard but did not fix the entry length check.

Меры по смягчению последствий

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Fixed version: 0.10.2

Затронутые пакеты

ПлатформаПакетСостояниеРекомендацияРелиз
Red Hat Enterprise Linux 10swtpmFix deferred
Red Hat Enterprise Linux 8virt:rhel/swtpmFix deferred
Red Hat Enterprise Linux 9swtpmFix deferred

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Дополнительная информация

Статус:

Moderate
Дефект:
CWE-125
https://bugzilla.redhat.com/show_bug.cgi?id=2517910swtpm: swtpm: Out-of-bounds read in SWTPM_NVRAM_CheckHeader due to sizeof(pointer) vs sizeof(struct) mismatch

6.1 Medium

CVSS3

Связанные уязвимости

CVSS3: 6.1
ubuntu
30 дней назад

An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.

CVSS3: 6.1
nvd
30 дней назад

An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.

msrc
27 дней назад

Swtpm: swtpm: out-of-bounds read in swtpm_nvram_checkheader due to sizeof(pointer) vs sizeof(struct) mismatch

CVSS3: 6.1
debian
30 дней назад

An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_C ...

CVSS3: 6.1
github
30 дней назад

An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.

6.1 Medium

CVSS3