CVE-2024-26582
Description
A use-after-free vulnerability was found in the tls subsystem of the Linux kernel. The tls_decrypt_sg() function doesn't take references on the pages from clear_skb, so the put_page() in tls_decrypt_done() releases them and a use-after-free can be triggered in process_rx_list when trying to read from the partially-read skb. This issue could lead to a denial of service condition or code execution.
Statement
Red Hat Enterprise Linux 6 and 7 are not affected by this CVE as they did not include kernel TLS support (upstream commit 3c4d755). Red Hat Enterprise Linux 8 is not affected as it did not include the upstream commit that introduced this flaw (fd31f39 "tls: rx: decrypt into a fresh skb").
Mitigation
No current mitigation is available for this vulnerability. Please make sure to have kernel up-to-date as soon as the patches are available to make sure the flaw mitigated.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.8 | 7.8 | 9.8 |
| Attack Vector | Local | Local | Network |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | High | High |
| Integrity Impact | Low | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
Only local user with some privileges can trigger it, so AV:L and PR:L. From the description "partial reads and async decrypt" means that attack requires few conditions simultaneously, so it is complex (AC:H). It is expected that only fail could happen, but unlikely can be used for privileges escalation, so only A:H and CI:L.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
