CyberSecBulletin
CVE-2014-0196Exploited in the wildNVD status: Analyzed

Linux Kernel Race Condition

Published Updated By the CyberSecBulletin desk

CVE-2014-0196 is a medium-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux Kernel from Linux, with a CVSS 2.0 base score of 6.9 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions 3.2.59, 3.4.91, 3.10.40 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 May 12, 2023, 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 3.2.59 or 3.4.91 or 3.10.40 or 3.12.20, whichever matches your release line, or a later version.
  2. CISA's required action: The impacted product is end-of-life and should be disconnected if still in use.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux Kernelafter 2.6.31 up to, but not including, 3.2.59; 3.3 up to, but not including, 3.4.91; 3.5 up to, but not including, 3.10.40; 3.11 up to, but not including, 3.12.20; 3.13 up to, but not including, 3.14.4; 2.6.313.2.59, 3.4.91, 3.10.40, 3.12.20, 3.14.4
DebianDebian Linux6.0; 7.0Not stated
Red HatEnterprise Linux6.0Not stated
Red HatEnterprise Linux EUS6.3; 6.4Not stated
Red HatEnterprise Linux Server EUS6.3Not stated
SUSESuse Linux Enterprise Desktop11Not stated
SUSESuse Linux Enterprise High Availability Extension11Not stated
SUSESuse Linux Enterprise Server11Not stated
OracleLinux6Not stated
CanonicalUbuntu Linux10.04; 12.04; 12.10; 13.10; 14.04Not stated
F5Big-ip Access Policy Manager11.1.0 through 11.5.1Not stated
F5Big-ip Advanced Firewall Manager11.3.0 through 11.5.1Not stated
F5Big-ip Analytics11.1.0 through 11.5.1Not stated
F5Big-ip Application Acceleration Manager11.4.0 through 11.5.1Not stated
F5Big-ip Application Security Manager11.1.0 through 11.5.1Not stated
F5Big-ip Edge Gateway11.1.0 through 11.3.0Not stated
F5Big-ip Global Traffic Manager11.1.0 through 11.5.1Not stated
F5Big-ip Link Controller11.1.0 through 11.5.1Not stated
F5Big-ip Local Traffic Manager11.1.0 through 11.5.1Not stated
F5Big-ip Policy Enforcement Manager11.3.0 through 11.5.1Not stated
F5Big-ip Protocol Security Module11.1.0 through 11.4.1Not stated
F5Big-ip Wan Optimization Manager11.1.0 through 11.3.0Not stated
F5Big-ip Webaccelerator11.1.0 through 11.3.0Not stated
F5Big-iq Application Delivery Controller4.5.0Not stated
F5Big-iq Centralized Management4.6.0Not stated

Version data comes from NVD's product matching; 5 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Access vector
LocalLocal access is required.
Access complexity
MediumSome conditions must be met.
Authentication
NoneNo login is needed.
Confidentiality
CompleteAll data can be read.
Integrity
CompleteAny data can be modified.
Availability
CompleteThe system can be shut down completely.

Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.5MediumCISA (ADP)
CVSS 2.06.9MediumNVD

Official description

The n_tty_write function in drivers/tty/n_tty.c in the Linux kernel through 3.14.3 does not properly manage tty driver access in the "LECHO & !OPOST" case, which allows local users to cause a denial of service (memory corruption and system crash) or gain privileges by triggering a race condition involving read and write operations with long strings.

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

The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How developers prevent this class of flaw

  • In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
  • Use thread-safe capabilities such as the data access abstraction in Spring.
  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

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: partial).
  5. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Third-party and government advisories

Technical write-ups (may include proof of concept)

Other vulnerabilities in Linux Kernel

All Linux Kernel vulnerabilities

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