CVE-2021-36084

The libsepol library provides an API for the manipulation of SELinux binary policies. It is used by checkpolicy (the policy compiler) and similar tools, as well as by programs like load_policy that need to perform specific transformations on binary policies (for example, customizing policy boolean settings).

Security Fix(es):

• libsepol: use-after-free in __cil_verify_classperms() (CVE-2021-36084)

• libsepol: use-after-free in __cil_verify_classperms() (CVE-2021-36085)

• libsepol: use-after-free in cil_reset_classpermission() (CVE-2021-36086)

• libsepol: heap-based buffer overflow in ebitmap_match_any() (CVE-2021-36087)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.5 Release Notes linked from the References section.

The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __cil_verify_classpermission and __cil_pre_verify_helper).

The libsepol library provides an API for the manipulation of SELinux binary policies. It is used by checkpolicy (the policy compiler) and similar tools, as well as by programs like load_policy that need to perform specific transformations on binary policies (for example, customizing policy boolean settings).

Security Fix(es):

• libsepol: use-after-free in __cil_verify_classperms() (CVE-2021-36084)

• libsepol: use-after-free in __cil_verify_classperms() (CVE-2021-36085)

• libsepol: use-after-free in cil_reset_classpermission() (CVE-2021-36086)

• libsepol: heap-based buffer overflow in ebitmap_match_any() (CVE-2021-36087)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

Nicolas Iooss discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36084)

It was discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36085)

It was discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affects Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 21.10. (CVE-2021-36086)

It was discovered that libsepol incorrectly validated certain data, leading to a heap overflow. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36087)