SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-1000112

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch.

HIGH 7.0EPSS 20.8%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 20.8%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

Description

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.

CVSS 3.1
7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
20.80% probability · 97th percentile
CISA KEV
Not listed
Weakness
CWE-362
Affected
linux/linux kernel
Source
cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.