CyberSecBulletin
CVE-2024-50151NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2024-50151 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 6f0516ef1290da24b85461ed08a0938af7415e49, ed31aba8ce93472d9e16f5cff844ae7c94e9601d, e07d05b7f5ad9a503d9cab0afde2ab867bb65470 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 6f0516ef1290da24b85461ed08a0938af7415e49 or ed31aba8ce93472d9e16f5cff844ae7c94e9601d or e07d05b7f5ad9a503d9cab0afde2ab867bb65470 or 2ef632bfb888d1a14f81c1703817951e0bec5531, whichever matches your release line, or a later version.
  2. Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1.1 or a later version.
  3. Update Linux Kernel to 5.4.285 or 5.10.229 or 5.15.170 or 6.1.115, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxe77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, 6f0516ef1290da24b85461ed08a0938af7415e49; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, ed31aba8ce93472d9e16f5cff844ae7c94e9601d; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, e07d05b7f5ad9a503d9cab0afde2ab867bb65470; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, 2ef632bfb888d1a14f81c1703817951e0bec5531; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, b209c3a0bc3ac172265c7fa8309e5d00654f2510; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, fe92ddc1c32d4474e605e3a31a4afcd0e7d765ec; e77fe73c7e38c36145825d84cfe385d400aba4fd up to, but not including, 1ab60323c5201bef25f2a3dc0ccc404d9aca77f1; 5.06f0516ef1290da24b85461ed08a0938af7415e49, ed31aba8ce93472d9e16f5cff844ae7c94e9601d, e07d05b7f5ad9a503d9cab0afde2ab867bb65470, 2ef632bfb888d1a14f81c1703817951e0bec5531, b209c3a0bc3ac172265c7fa8309e5d00654f2510, fe92ddc1c32d4474e605e3a31a4afcd0e7d765ec
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1.1V1.1.1
LinuxLinux Kernel5.0 up to, but not including, 5.4.285; 5.5 up to, but not including, 5.10.229; 5.11 up to, but not including, 5.15.170; 5.16 up to, but not including, 6.1.115; 6.2 up to, but not including, 6.6.59; 6.7 up to, but not including, 6.11.6; 6.125.4.285, 5.10.229, 5.15.170, 6.1.115, 6.6.59, 6.11.6

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOBs when building SMB2_IOCTL request When using encryption, either enforced by the server or when using 'seal' mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command(). SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below: mount.cifs //srv/share /mnt -o ...,seal ln -s $(perl -e "print('a')for 1..1024") /mnt/link BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859 CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] print_report+0x156/0x4d9 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] ? __virt_addr_valid+0x145/0x310 ? __phys_addr+0x46/0x90 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] kasan_report+0xda/0x110 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] kasan_check_range+0x10f/0x1f0 __asan_memcpy+0x3c/0x60 smb2_set_next_command.cold+0x1d6/0x24c [cifs] smb2_compound_op+0x238c/0x3840 [cifs] ? kasan_save_track+0x14/0x30 ? kasan_save_free_info+0x3b/0x70 ? vfs_symlink+0x1a1/0x2c0 ? do_symlinkat+0x108/0x1c0 ? __pfx_smb2_compound_op+0x10/0x10 [cifs] ? kmem_cache_free+0x118/0x3e0 ? cifs_get_writable_path+0xeb/0x1a0 [cifs] smb2_get_reparse_inode+0x423/0x540 [cifs] ? __pfx_smb2_get_reparse_inode+0x10/0x10 [cifs] ? rcu_is_watching+0x20/0x50 ? __kmalloc_noprof+0x37c/0x480 ? smb2_create_reparse_symlink+0x257/0x490 [cifs] ? smb2_create_reparse_symlink+0x38f/0x490 [cifs] smb2_create_reparse_symlink+0x38f/0x490 [cifs] ? __pfx_smb2_create_reparse_symlink+0x10/0x10 [cifs] ? find_held_lock+0x8a/0xa0 ? hlock_class+0x32/0xb0 ? __build_path_from_dentry_optional_prefix+0x19d/0x2e0 [cifs] cifs_symlink+0x24f/0x960 [cifs] ? __pfx_make_vfsuid+0x10/0x10 ? __pfx_cifs_symlink+0x10/0x10 [cifs] ? make_vfsgid+0x6b/0xc0 ? generic_permission+0x96/0x2d0 vfs_symlink+0x1a1/0x2c0 do_symlinkat+0x108/0x1c0 ? __pfx_do_symlinkat+0x10/0x10 ? strncpy_from_user+0xaa/0x160 __x64_sys_symlinkat+0xb9/0xf0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08d75c13bb

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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