CVE-2023-53559
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-04

Last updated on: 2026-03-21

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ip_vti: fix potential slab-use-after-free in decode_session6 When ip_vti device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when ip_vti device sends IPv6 packets. As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets.
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Meta Information
Published
2025-10-04
Last Modified
2026-03-21
Generated
2026-06-16
AI Q&A
2025-10-04
EPSS Evaluated
2026-06-15
NVD
CVE-2023-53559
EUVD
EUVD-2025-32314
Affected Vendors & Products
Showing 15 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel From 4.15 (inc) to 4.19.293 (exc)
linux linux_kernel From 4.20 (inc) to 5.4.255 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.128 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.47 (exc)
linux linux_kernel From 5.5 (inc) to 5.10.192 (exc)
linux linux_kernel From 6.2 (inc) to 6.4.12 (exc)
linux linux_kernel 3.19
linux linux_kernel 3.19
linux linux_kernel From 3.19.1 (inc) to 4.14.324 (exc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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Mitigation Strategies

Apply the patch that fixes the slab-use-after-free vulnerability in the Linux kernel related to ip_vti and the sfb qdisc. Specifically, ensure your Linux kernel includes the commit that sets the cb field in the skb to 0 before sending IPv6 packets, as described in the fix for decode_session6.

Executive Summary

This vulnerability is a potential slab-use-after-free issue in the Linux kernel's ip_vti device when sending IPv6 packets. Specifically, when the ip_vti device is set to use the sfb type qdisc, the control block (cb) field of the sent socket buffer (skb) may be modified during enqueuing. Since the cb field is not properly reset before sending, this can lead to use-after-free errors. The fix involves setting the cb field in the skb to zero before sending packets to prevent this issue.

Impact Analysis

This vulnerability can cause memory corruption due to a use-after-free condition in the kernel when sending IPv6 packets via the ip_vti device. This could potentially lead to system instability, crashes, or exploitation by attackers to execute arbitrary code or cause denial of service.

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