Buffer overflow in Sophos Safeguard Easy Device Encryption Client
CVE-2018-6855
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 0x80202014. By crafting an input buffer we can control the execution path to the point where the constant 0xFFFFFFF will be written to a user-controlled address. We can take advantage of this condition to modify the SEP_TOKEN_PRIVILEGES structure of the Token object belonging to the exploit process and grant SE_DEBUG_NAME privilege. This allows the exploit process to interact with higher privileged processes running as SYSTEM and execute code in their security context.
Vulnerability class: Buffer Overflow
EPSS: 0.005 (42.5th percentile) — read the EPSS interpretation.
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.
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
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (x_refsource_CONFIRM, Patch, Vendor Advisory)
- cve@mitre.org (mailing-list, x_refsource_FULLDISC, Mailing List, Third Party Advisory, Issue Tracking)
- cve@mitre.org (Technical Description, Exploit, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2018-6855?
- CVE-2018-6855 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-2018-6855?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2018-6855 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.