Linux: Integer Underflow (Wrap or Wraparound)
CVE-2024-26828 is a critical-severity integer underflow (wrap or wraparound) vulnerability in Linux, with a CVSS 3.1 base score of 9.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 3babdcb5f1809a9a41e31547a063dedf6bb44cca, 7190353835b4a219abb70f90b06cdcae97f11512, f7ff1c89fb6e9610d2b01c1821727729e6609308 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 0.75% chance of exploitation within 30 days, higher than 56% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 3babdcb5f1809a9a41e31547a063dedf6bb44cca or 7190353835b4a219abb70f90b06cdcae97f11512 or f7ff1c89fb6e9610d2b01c1821727729e6609308 or df2af9fdbc4ddde18a3371c4ca1a86596e8be301, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.79 or 6.6.18 or 6.7.6, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | fe856be475f7cf5ffcde57341d175ce9fd09434b up to, but not including, 3babdcb5f1809a9a41e31547a063dedf6bb44cca; fe856be475f7cf5ffcde57341d175ce9fd09434b up to, but not including, 7190353835b4a219abb70f90b06cdcae97f11512; fe856be475f7cf5ffcde57341d175ce9fd09434b up to, but not including, f7ff1c89fb6e9610d2b01c1821727729e6609308; fe856be475f7cf5ffcde57341d175ce9fd09434b up to, but not including, df2af9fdbc4ddde18a3371c4ca1a86596e8be301; fe856be475f7cf5ffcde57341d175ce9fd09434b up to, but not including, cffe487026be13eaf37ea28b783d9638ab147204; 4.18 | 3babdcb5f1809a9a41e31547a063dedf6bb44cca, 7190353835b4a219abb70f90b06cdcae97f11512, f7ff1c89fb6e9610d2b01c1821727729e6609308, df2af9fdbc4ddde18a3371c4ca1a86596e8be301, cffe487026be13eaf37ea28b783d9638ab147204 |
| Linux | Linux Kernel | 4.18 up to, but not including, 6.1.79; 6.2 up to, but not including, 6.6.18; 6.7 up to, but not including, 6.7.6; 6.8 | 6.1.79, 6.6.18, 6.7.6 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.4 | Critical | CNA |
| CVSS 3.1 | 6.7 | Medium | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: cifs: fix underflow in parse_server_interfaces() In this loop, we step through the buffer and after each item we check if the size_left is greater than the minimum size we need. However, the problem is that "bytes_left" is type ssize_t while sizeof() is type size_t. That means that because of type promotion, the comparison is done as an unsigned and if we have negative bytes left the loop continues instead of ending.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Underflow (Wrap or Wraparound)
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
More Integer Underflow (Wrap or Wraparound) vulnerabilities (CWE-191)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Integer Underflow (Wrap or Wraparound) vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.4 High severity
- 7.3 High severity
- 7.8 High severity
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