# Onapsis Security Advisory 2021-0015: [Multiple CVEs] Memory Corruption vulnerability in SAP NetWeaver ABAP Dispatcher service ## Impact on Business An unauthenticated attacker without specific knowledge of the system can send a specially crafted packet over a network which will trigger an internal error in the system causing the system to crash and rendering it unavailable. ## Advisory Information - Public Release Date: 11/22/2021 - Security Advisory ID: ONAPSIS-2021-0015 - Researcher(s): Yvan Genuer ## Vulnerability Information - Vendor: SAP - Affected Components: All SAP kernel 32 and 64 bits, unicode and no-unicode - SAP KERNEL 7.22 - SAP KERNEL 7.22EXT - SAP KERNEL 7.49 - SAP KERNEL 7.53 - SAP KERNEL 7.73 - SAP KERNEL 7.77 - SAP KERNEL 7.81 - SAP KERNEL 8.04 (Check SAP Note 3021197 for detailed information on affected releases) - Vulnerability Class: CWE-20, CWE-125, CWE-476 - CVSS v3 score: 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Risk Level: High - Assigned CVE: CVE-2021-27628 CVE-2021-27607 - Vendor patch Information: SAP Security NOTE 3021197 ## Affected Components Description The SAP dispatcher service is part of SAP Kernel. Mandatory, it manage, gather and collect the requests from end users then forward them to work process. Without SAP dispatcher service, the SAP system is not able to process any users requests. ## Vulnerability Details CVE-2021-27607 : A NULL pointer dereference exist in `ThSncIn(REQUEST_BUF**, unsigned char)`, where `_Z10DpCaGetPtri` tries to read a part of input controlled by an attacker, then return 0x0 instead of a pointer to normal value if the input is 0xffffffff. CVE-2021-27628 : A memory corruption vulnerability exists for `DpRTmPrepareReq(DP_SESSION_INFO)` in Disp+work binary through the SAP Dispatcher service. If an attacker crafts a valid SAP Dispatcher packet, with valid header, but with a total packet size smaller than normal, the subtraction operation results in a negative value. Also if this negative value is anticipated and put in the same packet at a particular offset, the check operation that compares the two values will pass, and this value is used as size during the next operation. ## Solution SAP has released SAP Note 3021197 which provide patched versions of the affected components. The patches can be downloaded from https://launchpad.support.sap.com/#/notes/3021197. Onapsis strongly recommends SAP customers to download the related security fixes and apply them to the affected components in order to reduce business risks. ## Report Timeline - 02/01/2021: Onapsis sends details to SAP - 02/04/2021: SAP provides internal ID - 02/08/2021: SAP confirms CVSS - 06/09/2021: SAP releases SAP Note fixing the issue. - 11/21/2021: Advisory published ## References - Onapsis blogpost: https://www.onapsis.com/blog/sap-security-patch-day-june-2021-multiple-memory-corruption-vulnerabilities-can-lead-system - CVE Mitre: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-27607 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-27628 - Vendor Patch: https://launchpad.support.sap.com/#/notes/3021197 ## About Onapsis Research Labs Onapsis Research Labs provides the industry analysis of key security issues that impact business-critical systems and applications. Delivering frequent and timely security and compliance advisories with associated risk levels, Onapsis Research Labs combine in-depth knowledge and experience to deliver technical and business-context with sound security judgment to the broader information security community. Find all reported vulnerabilities at https://github.com/Onapsis/vulnerability_advisories ## About Onapsis, Inc. Onapsis protects the mission-critical applications that run the global economy, from the core to the cloud. The Onapsis Platform uniquely delivers actionable insight, secure change, automated governance and continuous monitoring for critical systems—ERP, CRM, PLM, HCM, SCM and BI applications—from leading vendors such as SAP, Oracle, Salesforce and others, while keeping them protected and compliant. 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