In the Linux kernel, the following vulnerability has been resolved:
isofs: bound Rock Ridge symlink components to the SL record
get_symlink_chunk() and the SL handling in
parse_rock_ridge_inode_internal() walk the variable-length components of
a Rock Ridge "SL" (symbolic link) record. Each component is a two-byte
header (flags, len) followed by len bytes of text, so it occupies
slp->len + 2 bytes. Both loops read slp->len and advance to the next
component, and get_symlink_chunk() additionally does
memcpy(rpnt, slp->text, slp->len), but neither checks that the component
lies within the SL record before dereferencing it.
A crafted SL record whose component declares a len that runs past the
record (rr->len) therefore triggers an out-of-bounds read of up to 255
bytes. When the record sits at the tail of its backing buffer - for
example a small kmalloc()ed continuation block reached through a CE
record - the read crosses the allocation; get_symlink_chunk() then
copies the out-of-bounds bytes into the symlink body returned to user
space by readlink(), disclosing adjacent kernel memory.
ISO 9660 images are routinely mounted from untrusted removable media -
desktop environments auto-mount them (e.g. via udisks2) without
CAP_SYS_ADMIN - so the record contents are attacker-controlled.
Reject any component that does not fit in the remaining record bytes
before using it. In get_symlink_chunk() return NULL, like the existing
output-buffer (plimit) checks, so a malformed record makes readlink()
fail with -EIO rather than silently returning a truncated target; in
parse_rock_ridge_inode_internal() stop the inode-size walk.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it