Vulnerabilities
- CVSS
- 8.2 High
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H- Risk score
- 65.6
- Published
- 2026-05-06
- Status
- Published
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_h323: fix OOB read in decode_choice()
In decode_choice(), the boundary check before get_len() uses the
variable `len`, which is still 0 from its initialization at the top of
the function:
unsigned int type, ext, len = 0;
...
if (ext || (son->attr & OPEN)) {
BYTE_ALIGN(bs);
if (nf_h323_error_boundary(bs, len, 0)) /* len is 0 here */
return H323_ERROR_BOUND;
len = get_len(bs); /* OOB read */
When the bitstream is exactly consumed (bs->cur == bs->end), the check
nf_h323_error_boundary(bs, 0, 0) evaluates to (bs->cur + 0 > bs->end),
which is false. The subsequent get_len() call then dereferences
*bs->cur++, reading 1 byte past the end of the buffer. If that byte
has bit 7 set, get_len() reads a second byte as well.
This can be triggered remotely by sending a crafted Q.931 SETUP message
with a User-User Information Element containing exactly 2 bytes of
PER-encoded data ({0x08, 0x00}) to port 1720 through a firewall with
the nf_conntrack_h323 helper active. The decoder fully consumes the
PER buffer before reaching this code path, resulting in a 1-2 byte
heap-buffer-overflow read confirmed by AddressSanitizer.
Fix this by checking for 2 bytes (the maximum that get_len() may read)
instead of the uninitialized `len`. This matches the pattern used at
every other get_len() call site in the same file, where the caller
checks for 2 bytes of available data before calling get_len().
Coverage 6
vulnerability
Multiple vulnerabilities have been discovered in the Linux kernel of Ubuntu. Several of these vulnerabilities allow for privilege escalation, data confidentiality breaches, and a security issue not specified by the publi…
vulnerability
Multiple vulnerabilities have been discovered in the Linux kernel of Ubuntu. Some of these vulnerabilities allow for privilege escalation, data confidentiality breaches, and data integrity compromise. These vulnerabiliti…
vulnerability
Multiple vulnerabilities have been discovered in the SUSE Linux kernel. Several of these vulnerabilities can lead to data confidentiality and integrity breaches, as well as the circumvention of security policies and deni…
vulnerability
Multiple vulnerabilities have been discovered in the SUSE Linux kernel. Some of these vulnerabilities allow for data confidentiality and integrity breaches, as well as bypassing security policies and causing denial of se…
threat-intel
Multiple vulnerabilities have been discovered in the Linux kernel of Ubuntu. Some of these vulnerabilities allow for privilege escalation, data confidentiality breaches, and denial of service attacks. The vulnerabilities…
threat-intel
Multiple vulnerabilities have been discovered in the SUSE Linux kernel. These vulnerabilities can lead to privilege escalation, denial of service, and data confidentiality breaches. The affected products range from deskt…
Advisories and references