A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Weakness
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Adaptive_security_appliance | Cisco | * | 9.7 (including) |
| Firepower_threat_defense | Cisco | * | 6.2.2 (including) |
| Firepower_threat_defense | Cisco | 6.2.3 (including) | 6.4.0.13 (excluding) |
| Firepower_threat_defense | Cisco | 6.5.0 (including) | 6.6.5 (excluding) |
| Firepower_threat_defense | Cisco | 6.7.0 (including) | 6.7.0.3 (excluding) |
| Firepower_threat_defense | Cisco | 7.0.0 (including) | 7.0.0 (including) |
| Adaptive_security_appliance_software | Cisco | 9.8 (including) | 9.8.4.40 (excluding) |
| Adaptive_security_appliance_software | Cisco | 9.9 (including) | 9.12.4.26 (excluding) |
| Adaptive_security_appliance_software | Cisco | 9.13 (including) | 9.14.3 (excluding) |
| Adaptive_security_appliance_software | Cisco | 9.15 (including) | 9.15.1.17 (excluding) |
| Adaptive_security_appliance_software | Cisco | 9.16 (including) | 9.16.1.28 (excluding) |
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].