SACK can cause extensive memory use via fragmented resend queue
Linux · Linux kernel
The TCP retransmission queue in the Linux kernel's tcp_fragment implementation, which handles TCP Selective Acknowledgment (SACK) sequences, can become fragmented in the Linux kernel. A remote attacker with network access, requiring no authentication or user interaction, can send crafted SACK sequences to cause excessive memory use and a denial of service.
Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit f070ef2ac66716357066b683fb0baf55f8191a2e.
- Exploited
- Not confirmed
- Reports
- 0
- Tactics
- 0/15
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
Disclosed on 18 Jun 2019. No public exploit code or confirmed exploitation is recorded.
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No techniques linkedNo ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.