cbcvebase.
CVE-2017-6327
published 2017-08-11

CVE-2017-6327: The Symantec Messaging Gateway before 10.6.3-267 can encounter an issue of remote code execution, which describes a situation whereby an individual may obtain…

PriorityP190high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2022-05-03
Exploited in the wild
EPSS
35.34%
98.2th percentile
The Symantec Messaging Gateway before 10.6.3-267 can encounter an issue of remote code execution, which describes a situation whereby an individual may obtain the ability to execute commands remotely on a target machine or in a target process. In this type of occurrence, after gaining access to the system, the attacker may attempt to elevate their privileges.

Affected

2 ranges
VendorProductVersion rangeFixed in
symantecmessage_gateway< 10.6.3-26710.6.3-267
symantec_corporationmessaging_gateway

Detection & IOCsextracted from sources · hover to see the quote

url/brightmail/action1.do?method=notificationLogin
url/brightmail/admin/restore/action5.do?method=performRestore
url/brightmail/common.jsp
cookieJSESSIONID
port41002
path/opt/Symantec/Brightmail/cli/bin/db-restore
path/opt/Symantec/Brightmail/cli/sbin/db-restore
path/data/bcc/webapps/brightmail/output.txt
commandasdf`id>/data/bcc/webapps/brightmail/output.txt;/bin/uname -a>>/data/bcc/webapps/brightmail/output.txt`hehehe
othernotify=MTIzNDU2Nzg%3d6[...]
  • Detect unauthenticated GET requests to /brightmail/action1.do with method=notificationLogin, which is the authentication bypass entry point. The `notify` parameter carries a PBEWithMD5AndDES-encrypted payload.
  • Detect POST/GET requests to /brightmail/admin/restore/action5.do?method=performRestore containing shell metacharacters (backticks, semicolons) in the localBackupFileSelection parameter, indicating command injection attempts.
  • Monitor for the creation or access of /data/bcc/webapps/brightmail/output.txt, which is used by the exploit as a web-accessible command output drop file.
  • Alert on requests to /brightmail/common.jsp immediately followed by a performRestore request from the same session — this is the CSRF token harvesting step in the exploit chain.
  • Monitor the bmagent daemon on port 41002 for unexpected connections or invocations of db-restore with arguments containing shell metacharacters.
  • Detect execution of /usr/bin/du spawned from the db-restore perl script with arguments containing backtick-enclosed commands or semicolons, indicating command injection.
  • ·The authentication bypass relies on a static PBEWithMD5AndDES encryption password hardcoded in the application. The author deliberately withheld the exact password and a fully encrypted notify string from the public advisory.
  • ·The exploit chain requires three sequential steps: (1) authentication bypass via notificationLogin, (2) CSRF token retrieval from common.jsp, (3) command injection via performRestore. All three must succeed for full RCE.
  • ·The vulnerability affects Symantec Messaging Gateway prior to and including version 10.6.3-2; version 10.6.3-267 and later are patched.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.06.5MEDIUMAV:N/AC:L/Au:S/C:P/I:P/A:P
vulncheck8.8HIGH
cisa8.8HIGH
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.