8.4 HIGH
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Local (L)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): Low (L)
- User Interaction (UI): None (N)
- Scope (S): Changed (C)
- Confidentiality (C): High (H)
- Integrity (I): High (H)
- Availability (A): None (N)
- Modified Attack Vector (MAV): Local (L)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): Low (L)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): High (H)
- Modified Scope (MS): Changed (C)
- Modified Integrity (MI): High (H)
- Modified Availability (MA): None (N)
Activity log
- Created & dismissed (max. allowed matches exceeded) suggestion
memfd: deny writeable mappings when implying SEAL_WRITE
In the Linux kernel, the following vulnerability has been resolved: memfd: deny writeable mappings when implying SEAL_WRITE When SEAL_EXEC is added, SEAL_WRITE is implied to make W^X. But the implied seal is set after the check that makes sure the memfd can not have any writable mappings. This means one can use SEAL_EXEC to apply SEAL_WRITE while having writeable mappings. This breaks the contract that SEAL_WRITE provides and can be used by an attacker to pass a memfd that appears to be write sealed but can still be modified arbitrarily. Fix this by adding the implied seals before the call for mapping_deny_writable() is done.
References
Affected products
- <3be2a24f7f72ad7321ed6ad1715b956a4527bcf4
- =<6.18.*
- =<7.0.*
- =<6.12.*
- <3b041514cb6eae45869b020f743c14d983363222
- <0995d1f79aed8ccbf62056189dd53fd19726ea08
- =<*
- =<6.6.*
- <555702282d4536a865dfffb1cd4f6028f196e7e8
- <6.3
- <b3f4f82d1315f1439059a83d1c22c51a5b43d99e
- ==6.3