CVE Vulnerabilities

CVE-2020-11061

Heap-based Buffer Overflow

Published: Jul 10, 2020 | Modified: Jan 27, 2023
CVSS 3.x
7.4
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
CVSS 2.x
6 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

In Bareos Director less than or equal to 16.2.10, 17.2.9, 18.2.8, and 19.2.7, a heap overflow allows a malicious client to corrupt the directors memory via oversized digest strings sent during initialization of a verify job. Disabling verify jobs mitigates the problem. This issue is also patched in Bareos versions 19.2.8, 18.2.9 and 17.2.10.

Weakness

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Affected Software

Name Vendor Start Version End Version
Bareos Bareos 17.2.4 17.2.9
Bareos Bareos 18.4.1 19.2.7
Bareos Bareos 18.2.4 18.2.4
Bareos Bareos 18.2.4 18.2.4
Bareos Bareos 18.2.5 18.2.8
Bareos Bareos * 16.2.10

Potential Mitigations

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
  • D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
  • Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
  • Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
  • For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

References