CVE-2022-22204

An Improper Release of Memory Before Removing Last Reference vulnerability in the Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Juniper Networks Junos OS allows unauthenticated network-based attacker to cause a partial Denial of Service (DoS). On all MX and SRX platforms, if the SIP ALG is enabled, receipt of a specific SIP packet will create a stale SIP entry. Sustained receipt of such packets will cause the SIP call table to eventually fill up and cause a DoS for all SIP traffic. The SIP call usage can be monitored by show security alg sip calls. To be affected the SIP ALG needs to be enabled, either implicitly / by default or by way of configuration. Please verify on SRX with: user@host> show security alg status | match sip SIP : Enabled Please verify on MX whether the following is configured: [ services … rule (term ) from/match application/application-set ] where either a. name = junos-sip or an application or application-set refers to SIP: b. [ applications application application-protocol sip ] or c. [ applications application-set application junos-sip ] This issue affects Juniper Networks Junos OS on SRX Series and MX Series: 20.4 versions prior to 20.4R3-S2; 21.1 versions prior to 21.1R3-S2; 21.2 versions prior to 21.2R2-S2; 21.2 versions prior to 21.2R3; 21.3 versions prior to 21.3R2; 21.4 versions prior to 21.4R2. This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1. Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://kb.juniper.net/JSA69708