How severe is CVE-2009-4537?

CVE-2009-4537 has a CVSS 2.0 base score of 7.8, rated high severity.

Is CVE-2009-4537 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4537?

CVE-2009-4537 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-4537?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2009-4537 published?

CVE-2009-4537 was published on 2010-01-12 and last updated on 2026-06-16.

CVE-2009-4537

CVE-2009-4537 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 2.0 base score 7.8)
EPSS exploit prediction: 6% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Linux Linux Kernel
Published: 2010-01-12
Last modified: 2026-06-16

Description

drivers/net/r8169.c in the r8169 driver in the Linux kernel 2.6.32.3 and earlier does not properly check the size of an Ethernet frame that exceeds the MTU, which allows remote attackers to (1) cause a denial of service (temporary network outage) via a packet with a crafted size, in conjunction with certain packets containing A characters and certain packets containing E characters; or (2) cause a denial of service (system crash) via a packet with a crafted size, in conjunction with certain packets containing '\0' characters, related to the value of the status register and erroneous behavior associated with the RxMaxSize register. NOTE: this vulnerability exists because of an incorrect fix for CVE-2009-1389.

Frequently asked questions

What is CVE-2009-4537?: drivers/net/r8169.c in the r8169 driver in the Linux kernel 2.6.32.3 and earlier does not properly check the size of an Ethernet frame that exceeds the MTU, which allows remote attackers to (1) cause a denial of service (temporary network outage) via a packet with a crafted size, in conjunction with certain packets containing A characters and certain packets containing E characters; or (2) cause a denial of service (system crash) via a packet with a crafted size, in conjunction with certain packets containing '\0' characters, related to the value of the status register and erroneous behavior associated with the RxMaxSize register. NOTE: this vulnerability exists because of an incorrect fix for CVE-2009-1389.
How severe is CVE-2009-4537?: CVE-2009-4537 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2009-4537 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-4537?: CVE-2009-4537 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-4537?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2009-4537 published?: CVE-2009-4537 was published on 2010-01-12 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:5.0:*:*:*:*:*:*:*

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