Microsoft Edge Scripting Engine RemoveEmptyLoopAfterMemOp memory corruption

CVSS Meta Temp Score
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5.8$0-$5k0.00

A vulnerability classified as critical has been found in Microsoft Edge (Web Browser) (affected version unknown). Affected is the function BackwardPass::RemoveEmptyLoopAfterMemOp of the component Scripting Engine. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

ChakraCore and Windows 10 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-11886, CVE-2017-11889, CVE-2017-11890, CVE-2017-11893, CVE-2017-11894, CVE-2017-11895, CVE-2017-11901, CVE-2017-11903, CVE-2017-11905, CVE-2017-11905, CVE-2017-11907, CVE-2017-11908, CVE-2017-11910, CVE-2017-11911, CVE-2017-11912, CVE-2017-11913, CVE-2017-11914, CVE-2017-11916, CVE-2017-11918, and CVE-2017-11930.

The bug was discovered 12/12/2017. The weakness was presented 12/12/2017 by lokihardt with Google Project Zero as KB4053579 as confirmed security update guide (Website). The advisory is available at portal.msrc.microsoft.com. This vulnerability is traded as CVE-2017-11909 since 07/31/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. Technical details and a public exploit are known. The advisory points out:

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Microsoft Edge. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

A public exploit has been developed by Google Security Research and been published 4 weeks after the advisory. The exploit is shared for download at exploit-db.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 105180 (KB4053579: Windows 10 Version 1607 and Windows Server 2016 December 2017 Security Update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 91416 (Microsoft Edge Security Update for December 2017). The code used by the exploit is:

function opt(a, b, always_true = true) {
    a[0] = 1234;
    b[0] = 0;
 
    let arr = a;
    if (always_true) {
        arr = b;
        for (let i = 0; i < arr.length; i++)
            arr[i] = 0;
    }
 
    let val = arr[0];
    if (val) {
        print(val);  // Must be 0, but prints out 1234
        return true;
    }
 
    return false;
}
 
let a = new Uint32Array(1);
let b = new Uint32Array(0x1000);
for (let i = 0; i < 10000; i++) {
    if (opt(a, b)) {
        break;
    }
}

Applying the patch KB4053579 is able to eliminate this problem. The bugfix is ready for download at catalog.update.microsoft.com. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (43467), Tenable (105180) and SecurityFocus (BID 102085†). See VDB-110525, VDB-110526, VDB-110528 and VDB-110530 for similar entries. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 5.8

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 4.2
Vendor Vector (Microsoft): 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Google Security Research
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 105180
Nessus Name: KB4053579: Windows 10 Version 1607 and Windows Server 2016 December 2017 Security Update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 56516
OpenVAS Name: Microsoft Windows Multiple Vulnerabilities (KB4054517)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍

Patch: KB4053579

Timelineinfo

07/31/2017 🔍
12/12/2017 +134 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/13/2017 +1 days 🔍
01/09/2018 +27 days 🔍
01/09/2018 +0 days 🔍
06/14/2024 +2348 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: KB4053579
Researcher: lokihardt
Organization: Google Project Zero
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-11909 (🔍)
GCVE (CVE): GCVE-0-2017-11909
GCVE (VulDB): GCVE-100-110538

OVAL: 🔍

SecurityFocus: 102085 - Microsoft Edge Scripting Engine CVE-2017-11909 Remote Memory Corruption Vulnerability
SecurityTracker: 1039990

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 12/13/2017 07:54 AM
Updated: 06/14/2024 09:49 PM
Changes: 12/13/2017 07:54 AM (98), 12/24/2019 03:07 PM (7), 01/27/2021 07:16 AM (2), 06/14/2024 09:49 PM (16)
Complete: 🔍
Cache ID: 18:804:40

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