CyberSecBulletin
CVE-2024-50301NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2024-50301 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 c3ce634ad953ce48c75c39bdfd8b711dd95f346f, 4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d, 1e4332581cd4eed75aea77af6f66cdcdda8b49b9 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 c3ce634ad953ce48c75c39bdfd8b711dd95f346f or 4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d or 1e4332581cd4eed75aea77af6f66cdcdda8b49b9 or 199c20fb7499c79557a075dc24e9a7dae7d9f1ce, whichever matches your release line, or a later version.
  2. Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
  3. Update SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxb2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, c3ce634ad953ce48c75c39bdfd8b711dd95f346f; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 1e4332581cd4eed75aea77af6f66cdcdda8b49b9; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 199c20fb7499c79557a075dc24e9a7dae7d9f1ce; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, bbad2d5b6c99db468d8f88b6ba6a56ed409b4881; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 3e79ad156bedf2da0ab909a118d2cec6c9c22b79; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, e0a317ad68e4ea48a0158187238c5407e4fdec8b; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 4a74da044ec9ec8679e6beccc4306b936b62873f; and 1 more rangesc3ce634ad953ce48c75c39bdfd8b711dd95f346f, 4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d, 1e4332581cd4eed75aea77af6f66cdcdda8b49b9, 199c20fb7499c79557a075dc24e9a7dae7d9f1ce, bbad2d5b6c99db468d8f88b6ba6a56ed409b4881, 3e79ad156bedf2da0ab909a118d2cec6c9c22b79
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1.1V1.1.1
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensRUGGEDCOM RST2428Pbefore V3.2V3.2
SiemensSCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 familybefore V3.2V3.2
SiemensSCALANCE XCM-/XRM-/XCH-/XRH-300 familybefore V3.2V3.2
LinuxLinux Kernel3.13 up to, but not including, 4.19.324; 4.20 up to, but not including, 5.4.286; 5.5 up to, but not including, 5.10.230; 5.11 up to, but not including, 5.15.172; 5.16 up to, but not including, 6.1.117; 6.2 up to, but not including, 6.6.61; 6.7 up to, but not including, 6.11.8; 6.124.19.324, 5.4.286, 5.10.230, 5.15.172, 6.1.117, 6.6.61

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
NoneNothing can be modified.
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:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.1HighNVD
CVSS 3.17.1HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: security/keys: fix slab-out-of-bounds in key_task_permission KASAN reports an out of bounds read: BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36 BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline] BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410 security/keys/permission.c:54 Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362 CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:123 print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 __kuid_val include/linux/uidgid.h:36 [inline] uid_eq include/linux/uidgid.h:63 [inline] key_task_permission+0x394/0x410 security/keys/permission.c:54 search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793 This issue was also reported by syzbot. It can be reproduced by following these steps(more details [1]): 1. Obtain more than 32 inputs that have similar hashes, which ends with the pattern '0xxxxxxxe6'. 2. Reboot and add the keys obtained in step 1. The reproducer demonstrates how this issue happened: 1. In the search_nested_keyrings function, when it iterates through the slots in a node(below tag ascend_to_node), if the slot pointer is meta and node->back_pointer != NULL(it means a root), it will proceed to descend_to_node. However, there is an exception. If node is the root, and one of the slots points to a shortcut, it will be treated as a keyring. 2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function. However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as ASSOC_ARRAY_PTR_SUBTYPE_MASK. 3. When 32 keys with the similar hashes are added to the tree, the ROOT has keys with hashes that are not similar (e.g. slot 0) and it splits NODE A without using a shortcut. When NODE A is filled with keys that all hashes are xxe6, the keys are similar, NODE A will split with a shortcut. Finally, it forms the tree as shown below, where slot 6 points to a shortcut. NODE A +------>+---+ ROOT | | 0 | xxe6 +---+ | +---+ xxxx | 0 | shortcut : : xxe6 +---+ | +---+ xxe6 : : | | | xxe6 +---+ | +---+ | 6 |---+ : : xxe6 +---+ +---+ xxe6 : : | f | xxe6 +---+ +---+ xxe6 | f | +---+ 4. As mentioned above, If a slot(slot 6) of the root points to a shortcut, it may be mistakenly transferred to a key*, leading to a read out-of-bounds read. To fix this issue, one should jump to descend_to_node if the ptr is a shortcut, regardless of whether the node is root or not. [1] https://lore.kernel.org/linux-kernel/[email protected]/ [jarkko: tweaked the commit message a bit to have an appropriate closes tag.]

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

The underlying weakness: Out-of-bounds Read

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

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

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

References

Recent Out-of-bounds Read vulnerabilities

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