Buffer overflow in Sophos Safeguard Easy Device Encryption Client
CVE-2018-6856
Sophos SafeGuard Enterprise before 8.00.5, SafeGuard Easy before 7.00.3, and SafeGuard LAN Crypt before 3.95.2 are vulnerable to Local Privilege Escalation via IOCTL 0x8020601C. By crafting an input buffer we can control the execution path to the point where a global variable will be written to a user controlled address. We can take advantage of this condition to zero-out the pointer to the security descriptor in the object header of a privileged process or modify the security descriptor itself and run code in the context of a process running as SYSTEM.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (47.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Sophos Safeguard Easy Device Encryption Client — versions 6.00, 6.10, 7.00
- Sophos Safeguard Enterprise Client — versions 5.60.3, 6.00, 6.00.1
- Sophos Safeguard Lan Crypt Client — versions 3.90.1, 3.90.2, 3.95.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- community.sophos.com/kb/en-us/131934 (Patch, Vendor Advisory)
- seclists.org/fulldisclosure/2018/Jul/20 (mailing-list, Mailing List, Third Party Advisory)
- labs.nettitude.com/blog/cve-2018-6851-to-cve-2018-6857-sophos-privilege-escalat… (Technical Description, Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-6856?
- CVE-2018-6856 is a high-severity vulnerability in Sophos Safeguard Easy Device Encryption Client, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2018-07-09.
- How severe is CVE-2018-6856?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2018-6856 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.