| Severity |
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| Remote |
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| Type |
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| Description |
| + |
An integer overflow has been discovered in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). A sequence of SACKs may be crafted such that one can trigger a kernel panic. A remote attacker could use this to cause a denial of service (system crash). |
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| References |
| + |
https://www.openwall.com/lists/oss-security/2019/06/17/5 |
| + |
https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.md |
| + |
https://access.redhat.com/security/vulnerabilities/tcpsack |
| + |
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3b4929f65b0d8249f19a50245cd88ed1a2f78cff |
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| Notes |
| + |
Workaround: |
| + |
|
| + |
$ sudo sysctl -w net.ipv4.tcp_sack=0 |
| + |
net.ipv4.tcp_sack = 0 |
| + |
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| + |
IMPORTANT: The sysctl modification shown above is not persistent across reboots |
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