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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.208 (97.5th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.208 · newest: 0.208 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- seclists.org/oss-sec/2017/q3/277 (mailing-list, Patch, Mailing List, Third Party Advisory)
- access.redhat.com/errata/RHSA-2017:3200 (vendor-advisory, Third Party Advisory)
- www.securityfocus.com/bid/100262 (VDB Entry, Third Party Advisory, vdb-entry)
- access.redhat.com/errata/RHSA-2017:2918 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2017:2931 (vendor-advisory, Third Party Advisory)
- www.debian.org/security/2017/dsa-3981 (vendor-advisory, Third Party Advisory)
- github.com/xairy/kernel-exploits/tree/master/CVE-2017-1000112 (Third Party Advisory)
- www.securitytracker.com/id/1039162 (VDB Entry, Third Party Advisory, vdb-entry)
- www.exploit-db.com/exploits/45147/ (VDB Entry, Third Party Advisory, exploit)
- access.redhat.com/errata/RHSA-2017:2930 (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.