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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 6 Oct 2022.
Linux KernelOperating system · Linux

CVE-2013-2596

HIGH · 7.8 CVSS v3.1 Published 2013-04-13
Fix available
A fix is available. Upgrade to 3.0.75 / 3.2.45 or later.
See remediation →
96/100
Remediation priority · Urgent
In the wild Public exploit Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Integer overflow vulnerability in the fb_mmap function in Linux kernel's drivers/video/fbmem.c (prior to 3.8.9) allows local users to map the entirety of kernel memory read-write via crafted mmap2 system calls on /dev/graphics/fb0, leading to privilege escalation. The flaw lacks proper bounds checking on framebuffer memory mapping parameters.

MitigationUpdate Linux kernel to version 3.8.9 or later, or apply the equivalent backported patch for the fb_mmap integer overflow fix; for Android devices, apply vendor-specific OTA updates.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.12, < 3.0.75>= 3.1, < 3.2.45>= 3.3, < 3.4.42>= 3.5, < 3.8.9
AndroidOperating system
Affected:= 4.1.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version against affected ranges
    Run 'uname -r' or 'cat /proc/version' and compare the version to: >= 2.6.12 and < 3.0.75; >= 3.1 and < 3.2.45; >= 3.3 and < 3.4.42; >= 3.5 and < 3.8.9
    Affected if The kernel version falls within any of the listed vulnerable ranges AND the system has the framebuffer device accessible
  2. Verify framebuffer device exists
    Check for existence of /dev/graphics/fb0 (Android) or /dev/fb0 (Linux) using 'ls -la /dev/graphics/fb0' or 'ls -la /dev/fb0'
    Affected if The framebuffer device exists and is accessible to the user performing the check
  3. Check access permissions on framebuffer device
    Run 'ls -la /dev/graphics/fb0' or 'stat /dev/fb0' to view device file permissions and ownership
    Affected if The device has read-write permissions for the current user or a group the user belongs to, allowing mmap2 syscalls on it
  4. Confirm framebuffer subsystem is in use
    Check /sys/class/graphics/ for framebuffer devices or run 'cat /proc/fb' to list active framebuffers
    Affected if At least one framebuffer device is active and registered with the kernel's fbmem subsystem

A system is affected if it runs a vulnerable Linux kernel version within the specified ranges AND has an accessible /dev/graphics/fb0 or /dev/fb0 device with mmap permissions for the user.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.0.75 / 3.2.45 / 3.4.42 or later
Fixed in 3.0.753.2.453.4.42
Vendor patch marc.info →
Interim mitigation

Update Linux kernel to version 3.8.9 or later, or apply the equivalent backported patch for the fb_mmap integer overflow fix; for Android devices, apply vendor-specific OTA updates.

Recommended fix High confidence

Linux Kernel 3.8.9 (or branch-specific: 3.0.75+, 3.2.45+, 3.4.42+)

  1. Identify the currently running Linux kernel version using 'uname -r'
  2. Determine which branch your kernel version belongs to (2.6.12-3.0.x, 3.1.x, 3.2.x, 3.3-3.4.x, or 3.5-3.7.x)
  3. For 2.6.12 to 3.0.x: upgrade to Linux kernel 3.0.75 or later
  4. For 3.1.x: upgrade to Linux kernel 3.2.45 or later
  5. For 3.2.x to 3.4.x: upgrade to Linux kernel 3.4.42 or later
  6. For 3.5.x to 3.7.x: upgrade to Linux kernel 3.8.9 or later
  7. For 3.8.x and later: upgrade to the latest stable kernel release
  8. For Android 4.1.2 Motorola builds: apply the vendor-specific security update or patch level
Caveat Kernel upgrades may require rebuilding out-of-tree kernel modules; ensure driver compatibility before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Exploited in the wild — priority engagement
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2013-2596 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data