CyberSecBulletin
CVE-2013-2596Exploited in the wildNVD status: Analyzed

Linux Kernel Integer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2013-2596 is a high-severity integer overflow or wraparound vulnerability in Linux Kernel from 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 3.0.75, 3.2.45, 3.4.42 as the first without the flaw, so updating Linux Kernel to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on September 15, 2022, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Linux Kernel to 3.0.75 or 3.2.45 or 3.4.42 or 3.8.9, whichever matches your release line, or a later version.
  2. CISA's required action: Apply updates per vendor instructions.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux Kernel2.6.12 up to, but not including, 3.0.75; 3.1 up to, but not including, 3.2.45; 3.3 up to, but not including, 3.4.42; 3.5 up to, but not including, 3.8.93.0.75, 3.2.45, 3.4.42, 3.8.9
MotorolaAndroid4.1.2Not stated

Version data comes from NVD's product matching. 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 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)
CVSS 2.06.9MediumNVD

Official description

Integer overflow in the fb_mmap function in drivers/video/fbmem.c in the Linux kernel before 3.8.9, as used in a certain Motorola build of Android 4.1.2 and other products, allows local users to create a read-write memory mapping for the entirety of kernel memory, and consequently gain privileges, via crafted /dev/graphics/fb0 mmap2 system calls, as demonstrated by the Motochopper pwn program.

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

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Linux Kernel

All Linux Kernel vulnerabilities

Recent Integer Overflow or Wraparound vulnerabilities

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