Vulnerability in Linux Kernel

CVE-2017-1000112

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. When building a UFO packet with MSG_MORE __ip_append_data() calls ip_ufo_append_data() to append. However in between two send() calls, the append path can be switched from UFO to non-UFO one, which leads to a memory corruption. In case UFO packet lengths exceeds MTU, copy = maxfraglen - skb->len becomes negative on the non-UFO path and the branch to allocate new skb is taken. This triggers fragmentation and computation of fraggap = skb_prev->len - maxfraglen. Fraggap can exceed MTU, causing copy = datalen - transhdrlen - fraggap to become negative. Subsequently skb_copy_and_csum_bits() writes out-of-bounds. A similar issue is present in IPv6 code. The bug was introduced in e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") on Oct 18 2005.

Vulnerability class: Race Condition

EPSS: 0.208 (97.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (mailing-list, x_refsource_MLIST, Patch, Mailing List, Third Party Advisory)
  • cve@mitre.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
  • cve@mitre.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_BID)
  • cve@mitre.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
  • cve@mitre.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_SECTRACK)
  • cve@mitre.org (VDB Entry, Third Party Advisory, exploit, x_refsource_EXPLOIT-DB)
  • cve@mitre.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2017-1000112?
CVE-2017-1000112 is a high-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2017-10-05.
How severe is CVE-2017-1000112?
High severity. CVSS v3 base score is 7.0 out of 10.
Is CVE-2017-1000112 known to be exploited?
112 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.