Synology-SA-19:28 Linux kernel

Publish Time: 2019-06-21 17:59:00 UTC+8

Last Updated: 2022-09-06 14:19:08 UTC+8

Severity
Important
Status
Accepted

Abstract

CVE-2019-11477, CVE-2019-11478 and CVE-2019-11479 allow remote attackers to conduct denial-of-service attacks via a susceptible version of DiskStation Manager (DSM) or Synology Router Manager (SRM).

Affected Products

Product Severity Fixed Release Availability
DSM 6.2 Important Upgrade to 7.1.1-42962 or above.
SRM 1.2 Important Upgrade to 1.2.3-8017 or above.
VS Firmware 2.3 Important Will not fix

Mitigation

None

Detail

  • CVE-2019-11477

    • Severity: Important
    • CVSS3 Base Score: 7.5
    • CVSS3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    • Jonathan Looney discovered that the TCP_SKB_CB(skb)->tcp_gso_segs value was subject to an integer overflow in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). 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 3b4929f65b0d8249f19a50245cd88ed1a2f78cff.
  • CVE-2019-11479

    • Severity: Moderate
    • CVSS3 Base Score: 5.3
    • CVSS3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    • Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. 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 commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.
  • CVE-2019-11478

    • Severity: Moderate
    • CVSS3 Base Score: 5.3
    • CVSS3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    • 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.

Reference

Revision

Revision Date Description
1 2019-06-21 Initial public release.
2 2019-07-24 Update for SRM 1.2 is now available in Affected Products.
3 2022-08-10 Update for DSM 6.2 is now available in Affected Products.