CyberSecBulletin
CVE-2022-48948NVD status: Analyzed

Linux: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2022-48948 is a high-severity buffer copy without checking size of input 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 4972e3528b968665b596b5434764ff8fd9446d35, 06fd17ee92c8f1704c7e54ec0fd50ae0542a49a5, bc8380fe5768c564f921f7b4eaba932e330b9e4b 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 0.27% 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 4972e3528b968665b596b5434764ff8fd9446d35 or 06fd17ee92c8f1704c7e54ec0fd50ae0542a49a5 or bc8380fe5768c564f921f7b4eaba932e330b9e4b or b8fb1cba934ea122b50f13a4f9d6fc4fdc43d2be, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.337 or 4.14.303 or 4.19.270 or 5.4.229, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxcdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, 4972e3528b968665b596b5434764ff8fd9446d35; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, 06fd17ee92c8f1704c7e54ec0fd50ae0542a49a5; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, bc8380fe5768c564f921f7b4eaba932e330b9e4b; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, b8fb1cba934ea122b50f13a4f9d6fc4fdc43d2be; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, c79538f32df12887f110dcd6b9c825b482905f24; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, 6b41a35b41f77821db24f2d8f66794b390a585c5; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, 7b1f773277a72f9756d47a41b94e43506cce1954; cdda479f15cd13fa50a913ca85129c0437cc7b91 up to, but not including, d1a92bb8d697f170d93fe922da763d7d156b8841; and 2 more ranges4972e3528b968665b596b5434764ff8fd9446d35, 06fd17ee92c8f1704c7e54ec0fd50ae0542a49a5, bc8380fe5768c564f921f7b4eaba932e330b9e4b, b8fb1cba934ea122b50f13a4f9d6fc4fdc43d2be, c79538f32df12887f110dcd6b9c825b482905f24, 6b41a35b41f77821db24f2d8f66794b390a585c5
LinuxLinux Kernel2.6.35 up to, but not including, 4.9.337; 4.10 up to, but not including, 4.14.303; 4.15 up to, but not including, 4.19.270; 4.20 up to, but not including, 5.4.229; 5.5 up to, but not including, 5.10.161; 5.11 up to, but not including, 5.15.85; 5.16 up to, but not including, 6.0.15; 6.14.9.337, 4.14.303, 4.19.270, 5.4.229, 5.10.161, 5.15.85

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: Prevent buffer overflow in setup handler Setup function uvc_function_setup permits control transfer requests with up to 64 bytes of payload (UVC_MAX_REQUEST_SIZE), data stage handler for OUT transfer uses memcpy to copy req->actual bytes to uvc_event->data.data array of size 60. This may result in an overflow of 4 bytes.

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

The underlying weakness: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output 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 Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)

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 Buffer Copy without Checking Size of Input vulnerabilities

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