CVE-2010-1885
CriticalExploitedPublic exploitThe MPC::HexToNum function in helpctr.exe in Microsoft Windows Help and Support Center in Windows XP and Windows Server 2003 does not properly handle malformed escape sequences, which allows remote attackers to bypass the trusted documents whitelist (fromHCP option) and execute…
Published Jun 15, 2010 · Updated Apr 28, 2026
Key Facts
Patch immediately- CVE-2010-1885 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Windows 2003 Server (Microsoft), Windows Server 2003 (Microsoft), Windows Xp (Microsoft).
- It is exploited in the wild, listed in Industry KEV feed since Jul 26, 2011. Public exploit code is available.
- EPSS estimates a 71% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v2
9.3
AV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
71%
Higher than 99.4% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2010-1885 brief as a PDF
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Description
The MPC::HexToNum function in helpctr.exe in Microsoft Windows Help and Support Center in Windows XP and Windows Server 2003 does not properly handle malformed escape sequences, which allows remote attackers to bypass the trusted documents whitelist (fromHCP option) and execute arbitrary commands via a crafted hcp:// URL, aka "Help Center URL Validation Vulnerability."
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jul 26, 2011 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
6 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 2003 ServerMicrosoft | See advisory | n/a |
| Windows Server 2003Microsoft | See advisory | n/a |
| Windows XpMicrosoft | See advisory | n/a |
Timeline
Publicly disclosed
Jun 15, 2010
Added to Industry KEV feed
Jul 26, 2011
Last updated
Apr 28, 2026
Weakness Type
- CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
References
- advisoryhttp://blogs.technet.com/b/srd/archive/2010/06/10/help-and-support-center-vulnerability-full-disclosure-posting.aspx
- advisory40076
- advisoryhttp://www.microsoft.com/technet/security/advisory/2219475.mspx
- advisoryADV-2010-1417
- exploit20100609 Microsoft Windows Help Centre Handles Malformed Escape Sequences Incorrectly
FAQ
Common Questions.
The MPC::HexToNum function in helpctr.exe in Microsoft Windows Help and Support Center in Windows XP and Windows Server 2003 does not properly handle malformed escape sequences, which allows remote attackers to bypass the trusted documents whitelist (fromHCP option) and execute arbitrary commands via a crafted hcp://…
Affected: Windows 2003 Server (Microsoft); Windows Server 2003 (Microsoft); Windows Xp (Microsoft). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jul 26, 2011.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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